The screws I used are #8x1/2" lath. Drill 1/8" hole from the top through each lug you want a stud in then insert screw from the bottom. The amount of and placement of studs can vary depending on your needs, I have 80 in the rear and 120 in the front.
After all the studs are in the tire, take and old tube cut out the valve stem and cut the tube along the inside so it will wrap around a your inner tube (use a heavy duty tube with slime). Use a tire linner, I am using pond linner cut to fit.
My winter wear consists of ski bibs, down coat with outter coat, ear flap hat, neoprene face mask, goggles and,ski gloves all water and wind proof.