[header] How to convert bicycle tires into studded snow tires [title] Purchase the right supplies. [title] Drill (using a very small bit) down from the center of chosen knob into the tire. [title] Drill a screw up from inside-out. 
[step] If the angle isn't perpendicular to the tire, it'll stick out one side or the other. [substeps] Do one hole and screw at a time.