Hmm, thought it would be in the vid, but okay. I'll try to tell you what to do.
1. Go in Map Editor (duh)
2. On top of the screen you can see something which looks like Earth with tools at it. It's called ''Map Settings''.
Click on it.
3. Go the the 4th Tab of Map Settings, which is called ''Gamemodes''.
4. Then add Race to your gamemodes. Ofc you have to press Ok after you've done that.
5. On the left bottom you can see some icons with as ''headname'' Default. Go with your mouse to one of the icons and Scroll a little upwards. Your ''headname'' should change to Race then.
6. You can see a blue marker and that marker stand for Checkpoint.
7. You're done, enjoy mapping!
YOU CAN BE MY SAVING LIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIGHT