Forge Mod minecraft for magic launcher?

I'm currently in the 1.7.4 version of minecraft and I'm trying to install the forge mod for magic launcher, but when I try installing it, I get an error saying "you need to run 1.7.2 manually at least once." can you tell me, step - step, what this means and how do I run that version? I'm new to modding on minecraft

Added (1). can someone explain this

Run Minecraft > Patch it to 1.7."TWO" not 3 not 4 > Start Game > Close MC > Install it

You probably downloaded forge for 1.7.2 instead of 1.7.4. To get forge to work for 1.7.2, just open the minecraft launcher, and there should be a thing you can click at the bottom left of the window that says 'new profile' make a new profile, click use version: 1.7.2. Log in with it and then close minecraft and you should be able to install forge after that.

To get forge for 1.7.4, just download the correct file for 1.7.4. (And make sure you log in with the 1.7.4 profile at least once.)

Its a bit complicated to explain, so if i didn't explain it well, try searching 'how to make new profiles minecraft' on youtube or something along those lines.