How to separate the base from the monitor? Thank you.

The 912n does not have speakers so you will need separate speakers.

You have to remove four screws in order to separate the monitor base from the monitor.
Check the manual (section "Setting Up The Monitor", subsection "Removing The Monitor Base") for images of the location of the screws.
You can download the manual using this link: http://bizsupport2.austin.hp.com/bc/docs/support/SupportManual/c01129544/c01129544.pdf

Have you been to YOUTUBE for "lcd monitor disassembly" and "lcd monitor repair" video clips??? Absolutly do not use sharp cutting instruments to part the rear cover from front BEZEL of unit. One careless slip and it's a trip to local hospital "ER" to stop the gushing wound you have inflected on your body. Good luck with repair to your unit. 12fixlouie

I have the same problem as the original poster does. I have no idea how to get the base/stand actually out/separated from the monitor. I have tried pulling pretty hard and it wont budge.

Good day to you. This is simply a loose base connector problem. The best way to tighten the base onto the monitor is to apply adhesive pastes like "mighty bond" or you can also tie a rubber bond onto it. Thank you and hope it helps.

You need to remove the two plastic hinges cover to get the stand off then you will see one more screw once the base is removed, more likely to have bad caps, see example here: http://s807.photobucket.com/home/budm/allalbums

Use very thin flat blade screw driver to separate the back cover from the front, starting at the bottom side first,

The base of the G19LWK can be removed but it takes a little work. You have to remove the black plastic case that sandwich the LCD screen. First remove all the screws on the backside of the monitor. Then, at the seam of the two casement halves, GENTLY pry the front screen frame away from the display. Work carefully all around the edge of the display to separate it a little at a time and the pull it away in one piece. Next you will find that the back casement is held to the display with plastic tabs around the perimeter. Carefully pry the tabs away from the display frame to separate and remove the back casement. Now the base mounting is exposed on the backside and held with 4 screws. Remove the screws and the base will come free. Re-assemble the casement by snapping the back on first followed by re-installing the screws. Then snap the front frame by lining of the plastic tabs and pressing the frame down evenly around the display. You are done!

1. Unplug the AC power cord to make sure the power is off.
turn the monitor upside down, you need 2 people for this.
2. Pull the 4 hooks on bottom side of the base and hold.
3. Separate the monitor and base.

Since you have surely looked, it isn't held on with exposed screws.
Check to make sure that the rounded area that allows tilting is not part of the case but appears to be separable.
Most that are removable are held by a tongue and a fairly obvious release tab.

if you can't remove the base, just place the monitor in the carton on good padding and upside down.
Fill and cushion the sides well, mark the carton with 'This side up' and an arrow and hope there are no malicious handlers on the trip.

I've shipped numerous monitors of different sizes and types and have lost none of them to shipping damage.

As per page 4 of the User's Manual from Acer:

Detaching the Monitor
If you need to repackage the monitor, please separate the monitor and base, and restore them to
the carton. To detach the monitor:
1. Unplug the AC power cord to make sure the power is off.
2. Pull the 4 hooks on bottom side of the base and hold.
3. Separate the monitor and base and put them into carton.