Remove the wheel and fork from your bike. Push the lock arm in from the bottom, lining it up in the fork slot. Insert the lock cylinder being careful to line it up so that the grove on the cylinder lines up with the predrilled hole on the fork (just below the bottom race) and that the round tab on the back of the lock cylinder properly lines up with the slot on the lock arm mechanism. I do it in the unlocked position with the key out of the cylinder. When I think I have everything lined up properly, I use a thin nail to make sure that it easily passes through the predrilled hole in the fork before inserting the peg that will hold everything securely. You can damage the cylinder if you try to force the peg when the cylinder groove is not in line with the hole. Before inserting the peg, turn the key to verify that the lock arm moves properly in the fork tube slot. When you are sure everything is lined up and functioning, using an awl and a hammer, drive the peg into the hole. Too much resistance may mean that the peg is out of line with the cylinder grove. If you are missing the peg, you can fabricate one from a nail that will fit tightly in the hole. To remove an improperly installed peg, just use an awl or nail to drive it out from the underside of the fork. I hope this helps. If you don't feel like doing this, I would be glad to take that lock off your hands (lol). I am looking for one for my 51 Columbia.
-patrick
