Replacing rear turning signal in 2000 ZX2

Are they accessible from inside the trunk or am I looking at pulling the tail light assembly?

I think it will be accessible from the back of the housing after you take it off the car. You should see a couple of screws on the lens assembly. Take them off and pull back on the housing. If it won't come off you have a pin in the side holding it. Carefully pry the housing on the side from the body of the car. Wrap the end of a screwdriver with a cloth so you don't ding the paint.