I hate incandescent bulbs! I also don't like ordering LED bulbs online. So I am lucky enough to have a Frys near by. I picked up about 5 epoxy sealed 12v LED SMD

Step 1: The Parts

Clear rubber/soft plastic bumpers (optional)
Linrose LED Modules (BIM1220W-White) [or any color u want/find]
Cut off disc/wheel or small hack saw (I like my Dremel)

Step 2: Tools

Small screwdriver set
Plastic wedge (I used my short finger nails)
Side cutters
Solder iron
Elec-Solder wire

Step 3: Remove Dome Light Fixture

I don' have a pic before the soldered finished product. Sorry.

wedge / pry
most likely clips on the sides (squeeze or compress)
slowly pull to the direction of least resistance
find wire harness (small flat head screw driver for tab [push end closest to you down] if you have clumsy fingers like mine) pull to separate connection

+- 90% of vehicles after 2000 wont have screws holding the dome light.

Step 4: Assessment of Setup

It is critical you determine what steps to take here! Not all cars are the same.

All I had to do was remove the clear plastic light diffuser to remove the bulb and place my LED module. Had my dome light been more shallow I would have needed to modify the bulb holder to accommodate the plastic light diffuser.

Find the Positive terminal (mark it)
Run your wiring (I had to do a little cutting as pointed out in the picture)
Temporarily secure the LED wire to your terminals and recheck you have power to the LED
Solder your joints

Step 5: Clean Up

Confirm joints are good, check fitment of plastic light diffuser, and retest power to LED

Step 6: Re-install

Connect Harness
Check functionality (On/doorOn)
Push back into place as you did when removing (path of least resistance)
May have to give good kick (push) to get the clips to hold it tight against the headliner
Re-check functionality (On/doorOn)

All Done!