How to replace wheel?
One of the wheels of the Marathon FC9200 broke off. I bought a new one, but I don't know how to attach it. There is an additional part (red) that is located in the axle, but I don't know if you should put it in the whole and then attch teh wheel, or put it in the axle before attching the wheel to the cleaner. If I try to follow the secon possibility, I feel much resistance and am afraid that I will break either the wheel or the hole into which the wheel should be attached.