Find your radio code so that when you disconnect the battery neg cable, you will be able to reset your radio.
On a 2000 CRV it was very easy. Can't remember if it was a nut or a couple of screws and the button switch just pulled right out.
Make sure you disconnect the battery before you remove the switch in case you short out the switch wire accidentally.
On that CRV, the door switch was fine, but I had to shim it so that it would work.
The radio code is usually found in the glove box, upper left side. It can be found in other places sometime such as on the bottom of the ash tray, attached to the owner's manual. Someone must have it because whenever you disconnect the battery, you need to put the radio code in to get the radio working. The code is different for every vehicle. Perhaps you are talking about the switch that turns on the interior light. If you can find the right fuse to pull, you would not have to disconnect the battery. If you are real careful you may not even need to pull the fuse. That rubber boot should be removable (try putting a putty knife or a small screwdriver under the boot and gently prying up or research it more on Google. Once the boot is removed, it should be obvious what is holding the switch in. Look at your new switch.
You can also Google on how to find that radio code for your vehicle and/or use the search function in these forums.
The switch I shimmed was on the locking end of the door, opposite the hinge side. The reason I shimmed it was because it was not getting pushed in far enough to do its job, so I just shimmed it out about 1/32'.
Well the part was $4.04 genuine Honda part at Advanced Auto. The rubber exterior has a small round flap that covers the screw, a few turns of the Phillips pops off the switch, one wire plug come right off, snap on new switch, a few more turns of the Phillips head and it was done! The light comes on and the alarm sounds when the headlights are left on! Thanks guys!!!