I need to remove the crown from the movement

Removing the stem on a manual wind-up wrist watch can be a delicate task, as it requires some knowledge of watch mechanics. Here are the general steps to remove the stem on a Westclox W3 manual wind-up wrist watch:

1. Make sure that the watch is not wound.
2. Use a small screwdriver to remove the crown from the watch. This is typically done by gently pressing down on the crown and twisting it counterclockwise.
3. Once the crown is removed, you should be able to see the stem.
4. Use a stem removal tool to push the stem out of the movement. A stem removal tool is a specialized tool that is designed to remove stems from watches, it can be found in most watch repair kits.
5. Carefully remove the stem from the movement.
6. Once the stem is removed, you should be able to access the movement of the watch for repairs or maintenance.

"For servicing and repairs, the removal of the access screw on the back of the watch gives access to the stem release catch; after removal of the crown and stem, pressurised air is inserted to blow-out the crystal. Thereafter, the entire movement, together with the dial and hands are easily removed from the top. Experienced watchmakers with the necessary equipment should only perform this operation and the removal of the access-screw by any other persons without the required expertise is highly discouraged."

you can find what you need at Invicta Web-site http://invictawatch.com I had order straps from them for my Sabaqua NOMA III and russan diver here is also the link for the service http://www.invictawatch.com/support_files/service_center/ServiceCenter.htm

The repair for this problem may be quick and inexpensive--or somewhat more expensive. Either way, it's considered a minor repair.
The crown and stem assembly in held in a Rolex movement by a small pressure screw. When this screw is loosened, the stem can be cleanly pulled out of the movement without damaging any parts. The movement can then be removed from its case. If the screw is too loose, it is sometimes possible to pull the crown and stem out with ordinary effort. The simple fix for this would be to have a watchmaker take the back off your Rolex (requires a special wrench) and slide the stem back into the watch while loosening and re-tightening the screw. If that's it, the repair takes about 5 minutes, most of which is spent removing and replacing the watch back.
Things can get more complicated. The set stem interacts with a thin sheet metal spring / detent that helps the stem "snap" to its various set and wind positions. Sometimes, when a stem gets pulled out, the force of that can snap the delicate little finger in this watch part. Replacing this watch part will require that the movement be removed from the case and the hands and dial be removed for access to the part. Once you get to it, the part itself can easily be replaced--it's designed to be replaced without disassembling the whole watch movement--but there's considerably more effort involved than just sliding the stem back in and tightening down the screw.

Easier than you think.Pull your Crown out to the FIRST stop (were you would normally set your date). Push the "A" button (top chrono button) for your dial at the "3 oclock" area, Push the "B" button(bottom chron button) for the second hand.

Thank you for contacting FixYa.
I dont know why you want to remove the stem but here you go.
To remove the stem you must first loosen the set lever screw, then you can pull the stem out.
You only need to turn the set lever screw a couple turns to release the stem. Some movements use a button instead and in that case you would simply push the button down lightly with a pointed tool and while holding the button down pull the stem out.
For watches with one-piece cases where the movement comes out the dial side and the case has no removable back, you will not be able to get at the set lever screw. For this type of watch you must grasp the crown firmly and pull it out, or use plastic or soft brass tweezers to get behind the crown and pop it off. These watches have two-piece stems that have male and female ends that snap together. Then remove the bezel and let the movement come out into your hands. Then remove the hands and the dial and put the movement face down into a movement holder. Now you can remove the stem as described above

For Invicta chronographs to set the day you need to pull the crown out to position 3 (2nd click after releasing the crown/ furthest crown position/ same position to adjust time). You can only set the day by rotating the crown clockwise. Every 24 hours of clockwise rotation will move the day indicator forward 1 position (Mon>Tue, Tue>Wed, etc). If your watch is set one day ahead of the correct day (Its Tuesday but the watch displays Wednesday for example) you will need to rotate the crown clockwise through the entire remainder of the week in order to get to the correct day, you CANNOT rotate the crown counter-clockwise in order to move the indicator back a day.

To remove the stem you must first loosen the set lever screw, then you can pull the stem out.
You only need to turn the set lever screw a couple turns to release the stem. Some movements use a button instead and in that case you would simply push the button down lightly with a pointed tool and while holding the button down pull the stem out.
For watches with one-piece cases where the movement comes out the dial side and the case has no removable back, you will not be able to get at the set lever screw. For this type of watch you must grasp the crown firmly and pull it out, or use plastic or soft brass tweezers to get behind the crown and pop it off. These watches have two-piece stems that have male and female ends that snap together. Then remove the bezel and let the movement come out into your hands. Then remove the hands and the dial and put the movement face down into a movement holder.

Easier than you think.
Pull your Crown out to the FIRST stop (were you would normally set your date). Push the "A" button (top chrono button) for your dial at the "3 oclock" area, Push the "B" button(bottom chron button) for the second hand.

If i were you , i'd contact directly the brand on their Official Website. This is best done by watchmaking specialists :
RAYMOND WEIL Swiss Watches