F1 2013 Okay, installing mods... but how to select the mod when you want to play it?

[Nemo1965]

Sorry guys, but I am getting quite desperate.

I've used the Ryder Mod Manager to install the 1970 mod into F1 2013... the manager says the mod has installed fine (green slash), I can see the files in the folders... but for the life of me I can't imagine how I SELECT the mod. So how do I play it?
The first time I installed it, it played... but the skins did not show. I de-installed, installed... the old game works fine... but again: I see no way to select the mod instead of the 'regular'game.

Help! It is driving me nuts.