Designing Kitchens and Bathrooms - wall mirror in bathroom

I want to remove a mirror in the bathroom. I assume it is stuck on with liquid nail. It is about 42x42inches. What is the best way to do this without damaging the wall behind it? I will be putting in a recessed medicine cabinet so some damage will not matter but the cabinet will not be as big as the mirror that is now there.

Mirror removal is a frequent topic on the Glass & Mirrors Forum.

The quickest method I have found is to:
Lay down heavy drop cloths to protect the vanity.
Score around the perimeter of the mirror with a utility knife to minimize drywall paper damage.
Score the mirror with a glass cutter every 6 inches on the vertical
Run duct tape every 10 inches on the horizontal
Place a slotted screwdriver behind the score line at the top and gently tape with a hammer to run the glass.
tap the front to continue the score line and remove each piece as you can. Eventually you will need to use a wide chizzel bevel face down to remove some sections.
As carefully as you can remove the paper of the drywall with adhesive still attached.

or

Cover with a drop cloth that drapes to the ground or vanity and hammer for a few minutes...Then remove by section.....

With all said and done it takes about 15 minutes to clear the wall and 30 to clean it up........WEAR GLOVES

Skim coat, sand, prime and paint........1 hr plus......

StephenS (Member). Bathroom Mirror Removal. Glass & Mirrors. DoItYourself.com. Posted 19 January 2002. Retrieved 17 November 2002. http://forum.doityourself.com/showthread.php?threadid=77466&highlight=mirror+removal

thank you so much, most useful help so far. :)