Battery change Black cover

Jerry, If its smooth on the back cover, you have to pry it off carefully. Get a magnifying glass and look around the cover edge, there should be a small under cut. Pry at this point with a penknife blade or similar. If the cover has 6 or 8 small indentations in it then it likely unscrews but you may still need to see a watch shop for the tool to unscrew it.
Fossil watches have a 2 year warranty so if its inside this, take it to a dealer.

The back of this watch doesn't pry off, it screws off.
I used the open tip of a needle-nose pliers to unscrew the back of the watch by inserting the the tips into opposing grooves in the back of the watch and turning it counter-clockwise.

Once the back of the watch is off, there are a few slotted screws that appear to hold a metal cover over the back of the watch 'guts', you'll need a jeweler's screwdriver to remove these screws (I counted 3 of them).

The battery is right under this cover.

When re-assembling the watch, I would apply a thin coat of sewing machine oil, or some other non-reactive lubricant, to the black gasket seal which should be on the back cover of the watch.

Turn the Suunto over to view the backside. Insert the quarter in the coin slot located on the battery compartment cover. Turn the coin counterclockwise to the "Open" position marked on the back of the case.

Remove the battery compartment cover. Remove the old battery from the battery compartment. Make sure the o-ring and all surfaces are clean, dry and not damaged. Do not stretch the o-ring!

Place the new battery into the battery compartment (negative side down, positive side up). Make sure the o-ring is in its place, as to keep the Suunto waterproof. Place the battery compartment cover back onto the backside of the watch.

Insert the quarter back into the coin slot and turn the coin clockwise to the "Close" position marked on the back of the case.

If this doesnt work take to a jeweler who has tools.
Jewel

Is there a chance that the illumination button is stuck? This would run the batter down in a few days.

mcdevito75 here, Depending on your watch itself, Basically you"d remove the back cover, then release any hold down linkages on the battery, then replace the battery, hold down linkages and cover. The BEST BET is to look for a small watch repair shop in your area for this battery replacement as it may take special jewelers screwdrivers to change the battery.

If you don't have the proper tools I recommend that you not do this yourself. You could scratch the case or damage the movement if you don't know what you're doing. If it's a water resistant watch the gasket also needs to be replaced once it is opened. DO NOT reuse a gasket! For about $8 any watch or jewelry store can change the battery and renew the gasket for you.

the metal cover will be sliding and if you will slide it left or right battery should come out.

Thanks

It either sets into a small groove on the back of the watch or it simply goes on the back cover and seats against the back of the watch when you re-install the cover to form a gasket to water proof the watch

Use this page to download a copy of CASIO watch manuals in PDF format. To download a PDF file, enter the four-digit (or three-digit) module number marked on the back cover of your watch.

http://world.casio.com/wat/download/en/manual/


You will need a pdf reader on your pc, you will find all instructions in there.