The collar is probably rusted to the bolt (the collar is #17 in the pic). The bolt goes in one side of ski, through the collar, and out the other side of the ski. The collar goes through two bi-metal bushings(#57) in the ski mount(#55, thing on the end of the pogo). Problem is the collar doesn't fit through the hole on the ski but the bolt turns because the collar will still turn in the bushings. Possible solutions: 1)Lots of WD40 (or similar product) and a big hammer(try not to damage the threads or mushroom the end of the bolt) 2) sawsall the bolt IF you can get the blade down between the ski and the soft aluminum ski mount 3) Get the torches out and sacrifice the ski, bolt and possibly the collar(it may need new bushings and a collar anyway) 4) Someone else makes a better suggestion.