At the school I use a 25 lb kettlebell but I only have a 10 lb at home.
Kettlebell swings: Use your hips and keep the kettle bell under control. Do not let it swing too far between your legs.
Rack (thats on the left): Point your elbow to the ground and rest the kettle bell on your arm. Try not lean to one side. Switch the kettlebell from one side to the other.
15 minutes is a long time! You can pause if you need to my not when it is in the rack position. Once you rack it you have to go! It sounds easy, but its hard.
Give it a try!