Place the washer, then the Allen bolt in the pulley and use the Allen wrench to screw it back into place.

Place the nut on the bolt and tighten by hand. Then use the adjustable wrench to tighten it completely.

Do not screw your nut on too tight. If the nut is too tight the pulley will not have a full range of motion and your equipment will seem stiff when you try and use it.

Once everything is set-up take your old pulley and dispose of it by taking it to the appropriate waste disposal company.