The spikes I used to create this look are called Screw Back Spikes and come in various sizes, colors & shapes. There are many internet sources to purchase them and I have provided links in the first step. I definitely recommend shopping around for different price points. Ebay seems to have some of the cheapest screwbacks, but they typically ship from Hong Kong, which can take a couple weeks to arrive.
If you've never used a power drill before, it's really no big deal. I recommended using an old shoe for practice first, before you start drilling holes in the heels you will use for this project.
I was able to create these shoes for less than $40 total, including shipping costs. (I already had the shoes).
Step 1: Tools & Equipment
Step 2: Drill holes in the back of the heels
After you have drilled the holes, take the head of the screw and punch it through the inside of the heel, so that it sticks out the backside. Next, take your desired spike and screw it on until it is tight.
Once you have finished screwing in all of your spikes, take a screwdriver and screw the screws tightly on unit they are flush with the shoe.