tub leak

Hello, I have a leak below the tee in my tub drain/overflow assembly. The tee floats freely on that narrower inner pipe, where the seal is completely lost. What's the best approach to replacing this drain setup (PVC?), and where do you suggest I begin/cut?

Sometimes we get calls about leaking tub drains. Here is one where the tub was refinished, and somebody used too much putty when installing the new parts on the old tub drain. The only thing that needs to seal on a tub drain, is a clean rubber seal between the tub and the drain shoe. Not...