Just the plastic one you turn.Just the plastic drain plug you turn or the threaded drain hole soldered to the housing?
What did you do with it? Looked like it was leaking a bit, slight turn and it spun right off!I’ve had that happen too; I was scared to ask
Drill out the middle, use an easy out?Auto parts stores have replacements, but you're going to have to use some ingenuity to remove the broken piece. Screwdriver, small needle nose pliers, etc. Getting the screwdriver's blade hot may allow it to be inserted into the broken half so it might be unscrewed.
Part that broke off is in the glove box; luckily it’s not leaking!What did you do with it? Looked like it was leaking a bit, slight turn and it spun right off!