Where is the radiator drain plug on a 2003 obs?

I've been smelling coolant this past week but I think its because my oil change guy topped off my coolant res. too much and now its over flowing.

Is there a drain plug on the res.?

My temp has been good even on a 100 mile drive but the coolant smell is buggin me. No smoke but there are bubbles in my res. if I pop the cap while its hot.