They don't wear out the way tires made with screws will. Step 2 View Figure B to get an idea of the hole pattern. The position of the holes to place the studs is critical to how the tire will perform. If you space the studs too far from the centerline of the tire, you will not get any straightline traction. From trial and error, I've found the best pattern is to stagger the studs about 30 degrees either side of the tire centerline.
Some tread patterns are better than others for being able locate studs.
Shop around for the best pattern, not the best tire. Step 3 Turn the tire inside out and spread it over the 2 x 4. While holding the body of the stud in place with the tips of the needle-nose pliers, hammer the stud through the holes from the inside out. Step 5 Go get that little girly ten-speed tire and cut off the wire bead on both sides. No need to be to accurate.