I have done it. What a pain in the ass it is. I ruined the one from the junk yard , so I completely took that one apart. I removed the belt and then took the good retractor from my rig and put the used belt on it. I struggled for 4 or more hours to get it all back together. And then all of a sudden. Plop. The whole thing went together in 45 second. Not really sure what I did differently. I did notice that the grease in both retraction wheels had hardened up. I would pull the cover and carefully lubricate both sides of the unit and cycle it If it works, be happy. If you pull the unit, make sure to zip tie the belt so that it does not retract the belt too far in the reel. If that happens then you are done and taking the whole thing apart. Good luck.