here's how he does it. You'll need a box of #8 panhead sheet metal screws, and a drill...

First, take the tires off the rims. Using a 3/32" drill bit, drill pilot holes from the outside of the knobby. This helps to get the screws started. Try to locate the holes from inside the tire then start screwing in your stud. If you have one, a cordless screwdriver can really help save your fingers.

After you get all the studs where you want them, use either an old inner tube slit lengthwise or buy some thin neoprene strips from a rubber supply store (I think it can go down to 1/32 thick) then use that to protect your inner tube. Use contact cement to keep it in place.

If you're afraid an inner tube may not offer enough protection, You can use an old Mtn. bike street tire instead. Cut off the beads (wires that hold the tire on the rim) and size to fit. If anyone knows how to improve on this, let me know.