This video describes how to disassemble newer (post ~2010) D-cell Mag-Lites (2, 3, 4, 5, or 6 cell). I believe the process is the same for C-cell Mag-Lites. The newer flashlights from Mag-Lite require a different driver than older models to remove the switch assembly. This works for the newer LED models too.
Tools needed: Torx #8 driver, electric powered grinder (such as a Dremel), safety glasses.
