Turn off the water before taking anything apart. If the shower has its own shut off, use it.
Otherwise the main water shut off for the entire house will need to be turned off. Place a blanket or towel in the shower to prevent chipping or scratching and also to prevent small parts from going down the drain.
Disassemble the old faucet by first removing the set screw in the side of the handle.
Remove the gray plastic disc that was directly under the handle. Remove the metal sleeve that slides over the whole assembly.
These two pieces should slide off by hand. Remove the brass ring that was under the metal sleeve that was just removed.
A strap wrench may be needed to remove the brass ring.
Remove the faucet assembly. It should have two parts to it, one part is blue and the other part is white.
Separate the two parts by simply pressing on the blue part and twisting.
Remove the rubber seats and the springs from the blue part and replace them with the new ones from the repair kit. Join the blue and white parts and twist together.
Reassemble the faucet by simply reversing the previous steps.