Mouse in headliner

I think there's a mouse in the headliner. It was squeaking and scratching around up there even with the car turned off. I pounded on the ceiling with my fist and I think it died. It stinks like a dead mouse. Trying to figure out how to take down the headliner or if it's too complicated, should I take it somewhere to have someone else do it? Please help. It stinks to high heaven!