Moby
GOLD Star
If they are intended to be rebuilt you can rebuild them. That's not intended to be a smart-a$$ reply. Lot's of things say for factory use only.
As @linuxgod says, the question is what tools are needed and can you get the parts. King/Fox/Radflo/Sway-a-Way are intended for easy service, parts, etc. They are designed to be easy to go into. That may not be the case here and more specialty tools required.
You may be ahead by just replacing them. Keep the springs and see if you can just get the dampners.
As @linuxgod says, the question is what tools are needed and can you get the parts. King/Fox/Radflo/Sway-a-Way are intended for easy service, parts, etc. They are designed to be easy to go into. That may not be the case here and more specialty tools required.
You may be ahead by just replacing them. Keep the springs and see if you can just get the dampners.