How do I replace the door switch for the overhead light on a 1995 toyota camry

I see you're still having lighting problems...

A switch for each door is mounted on the body pillar, just below the door striker.
It's covered by a protective rubber boot and held by a 10mm bolt. However the harness runs up inside the pillar. Removing brittle interior body components can be tricky.

Does the light work from the overhead switch?

If it does, the door switches are corroded, but may not need replaced. You'll need a small spray can of contact cleaner, a couple paper towels, and a small dose of patience.

FIRST: PLACE THE OVERHEAD SWITCH TO THE "OFF" POSITION

Gently pull the boot up from the bottom until the plunger is exposed. Note: you may need to push the plunger in to allow the boot to clear it. Once you have the plunger in view, push it in slightly and apply short spurts of the cleaner into the switch right beside the plunger and work the plunger by plucking it: push it in and let it snap back out. Some gentle wiggling will help, too. After each switch (as necc) is cleaned, turn on the over head and check the function of your "new" switch. Just don't forget to turn off the overhead, if you are doing more than one door.
I hope this helps.