Well, beginning at the brake rotor…
Unfortunately can a common brake rotor (without heavy mods) not be used, you will need an original brake disc.
At this opportunity to order spare parts you might also take a closer look at the snubber bearing, the 338 part (magnet spacer) and of course the freewheel.
The rear rotor is clamped by the freewheel, a special tool [size=200]T[/size]is required to remove it - do you have such thing?
As always, I’d recommend the purchase of a hook key [size=200]A[/size] for proper belt tensioning
For convenient belt changing you might use the step 13 of this thread.
(There should be also a few hints for belt, snubber and rear brake caliper un/remounting 
)
Did you already check the local parts availability?