How do you get the tail light lens off a 1996 Toyota Camry to change the tail light bulb?

The lens doesn't come off. Take the tail light assembly off and take the bulbs out of the rear. Here's how to remove a 1995 or 1996 Camry sedan's tail light assembly in order to replace a bulb. (Toyota makes this pretty complicated for this model.)

1) Detach the carpet from the trunk. Do this by removing the black pastic connectors that attach the carpet above where the tail light assembly is located. Place your thumbs behind the carpet and work the connectors out of the trunk by pushing and wiggling them. This is awkward and requires a good deal of force and patience.

2) Remove two nuts which attach the tail light assembly to the back of the car. Push the bolts through the sheet metal. (Sometimes the gasket on the tail light assembly sticks a little, but you should not need to apply nearly as much pressure as you did for the carpet connectors.)

3) Undo the two snaps which attach the tail light assembly to the side of the car. You can't see these snaps, so here's a description: Protruding from the tail light assembly are two metal pins. Attached to the car are two plastic sleeves which accept these pins. When you look under the carpet in the trunk, you can see the sleeves. The top one you can see in its entirety (eg: if it were transparent, you would be able to see the pin nestled inside of it.) However, the bottom one is of a different design; the only visible portion is merely an arm which juts out at a right angle to the sleeve in order to help anchor the sleeve. Undo the snaps by pulling the tail light assembly away from the side of the car (eg: in a direction perpendicular to the direction that the car would normally travel). Do this by grasping the tail light assembly with both hands and rocking it as you pull. These snaps can be very stubborn; I had to pull so hard that I was concerned the tail light assembly might break. Part of the difficulty is that the bottom pin tends to rust, which gives it a rough surface, which prevents it from sliding easily through the plastic sleeve. Once the tail light assembly has been worked out far enough to see behind it, I find it helps to insert a flat-head screwdriver and twist it to pry out the bottom pin. Once the assembly has been removed, you may want to smooth out any rusted pins with a metal brush and then put grease on them. The grease both lubricates and prevents future rust, thus making life easier the next time you need to remove the tail light assembly. Be aware that most lubricants, including most greases, tend to break down plastics slightly. However, this is the lesser of two evils; the scouring action of the rust would damage the plastic even more than the grease. If the pin is not rusted you may wish to leave it dry so as to protect the plastic.

4) Change the bulbs. They are accessible from the back of the tail light assembly. Removal is the same as for any automotive bulb. Twist the gray plastic socket to unlock it, then remove it from the tail light assembly. To unlock the bulb from the socket, push the bulb in and then twist it.

From a grateful reader: I used this method and it works, but I was able to get the assembly unstuck by spraying WD-40 on the white plastic sleeve of the top pin from inside the trunk. It immediately came free.