Help removing bathroom vent (pipe, cold, replacement, cement)

[Jedi5]

Looking to either fix or replace my bathroom vent.
Working with a Broan fan and before I go and make a mess, what do I need fix or replace it?

Draft coming in from the vent and I don't know if it is a damper that is broken or something else. From this diagran, do I need to remove the motor housing? There is conduit pipe behind the fan that I can't access to pull the fan down.

[akck]

You need to remove part 8 and all attached, to check out part 20, which is probably stuck in an open position.

[Jedi5]

Yep, I finally figured it out.

Was trying to fix the damper that is letting cold air in....

Thanks