Yes, it does all need to come out and you will need plenty of time to do it - this is not an evening's work!!
The bearings on the motor will have seized (they all do eventually) and you can get a replacement from Paddocks. Even when you have removed the heater, it is still a difficult job to remove the motor and you will need a lot of patience - I suggest making sure you have a workshop manual handy and making notes of where everything goes for re-assembly. Probably needs a full weekend unless you are far more skilled than me!
Good luck, Peter.