Just done exactly this.
Paddocks sell a kit, comes with all the gaskets you need (except swivel to axle) and all the seals you need (inc swivel seal, which you cant fit because your not removing the swivel co you have no gasket).
Ask for one seperately if you order from them.
You'll need to press or drift the roller bearing into the back of the stub, the oil seal goes in first :)
Stu.