How do I attach a mod to a weapon in New Vegas?

[Darkstar One]

Maybe I'm missing something here, but I can't for the life of me figure out how to attach a mod to a weapon here.  I have a few for my weapons, but I don't get the option to do so at a workbench.  Where do I do it?

[TK-421]

You do it from your inventory.

In the pip boy, go to your weapon inventory, highlight the weapon you want to modify and you should get an option to modify it.  It's listed with the repair option.  So on the PC it's R to repair and I think X to modify.

It works like the repair function only instead of a list of like items you would use to repair the weapon you instead get a list of available mods from your inventory.

So far I've created a custom .357 Magnum and added a Night Vision scope to a Varmint Rifle.

[Scuzz]

In the earlier versions didn't you need to be of a certain level/ability before you could do some repair things....?