Note that on the end of the switch opposite the push button, the metal is crimped in several places. This crimping prevent disassembly. Use a small flat bladed screwdriver and ball peen hammer to straighten out these crimps. Unscrew the tip of the push button and the shaft will slip out of the switch. Do not loose the small spring inside. The shaft has a flat rubber O-ring to seal against the inside walls of this essentially hollow switch. Often this rubber is cracked or worn and will not provide a seal against the wall. Using a vernier caliper, I measured the bore ID of the switch and the OD of the shaft. Replace the original flat O-ring with a standard round O-ring. After cleaning the switch & shaft, lubricate with a vacuum grease as used on a vacuum power brake booster. Reinsert the shaft, return spring and carefully re-crimp the end as original. My original switch performs like new in my 67 AC model and if it ever wears out again I can replace the O-ring for less than a dollar. It has been several years since I repaired my switch and do not want to disassemble my Vet to measure it again. Look up companies that sell bearings in the yellow pages and take your disassembled switch to them. They will have a vernier caliper to take the measurements and can supply you with the O-ring. For two bucks you can get a lifetime supply. Vacuum grease can be found at most auto parts stores. Remember you read this tip here first, so next year when you read this same tip in other catalogs, you will know who the sheep really are. Baaaaaaaaaa !