LG LMVM2055SB over the range microwave keys not...

Generally you unplug it, remove the screws in the grille to remove that, remove the screw in the top of the control panel frame, then lift up and out on the frame to ease it away from the chassis of the oven part way.

You will then be able to mark and/or photograph the wires so that you get each of them back where they should go. This is important.

Now the control panel assembly can be separated from the chassis.

Unlock and disconnect the green plastic strip - the part of the keypad that plugs into the circuit board.

Next, peel the old keypad off the frame, clean all the residue with Goo Gone, lighter fluid, or another solvent, clean it squeaky clean, the peel the backing off the new keypad and stick it on.

The reassembly is the reverse of the the disassembly.

We actually have the entire service manual for this one at our Web site: http://www.microwavedisplay.com/LMVM2055_Service_Manual.pdf

For future reference, I always recommend that users spray cleaner on a soft cloth then wipe the control panel.

And I always recommend non-ammonia cleaners since they can crack and damage plastic.