Myself. Just get M21 and a good applicator pad. Car should be washed and clean. Shake bottle, prime the applicator with the sealant and start applying. Apply to whole car, paint should be nice and cool, not in sunlight. Wait at least 20-25 minutes then start removing with a microfiber towel. And done! Once finished car should not be exposed to moisture or water for at least 12 hours, I think.
If you're really picky then you can give it another coat the next day, using the same procedure as above.
And if you're really picky about paint finish, you can apply something like Meguiar's Ultimate Polish first and then apply M21 Sealant.