I have a few mods I've removed from other weapons that currently sit in my inventory but I can't seem to figure out how to add then to an applicable weapon. I can only seem to create new mods for weapons and attach those at the weapon configuration benches. Any advice would be appreciated.

Thank you,

When you go to add a mod to a weapon, if you have that mod in your inventory, it will simply equip that instead of creating a new one. You'll know this has happened because instead of getting a pop-up showing what components are being pulled from what items, the mod will just automatically equip; there will be no pop-up. This happens automatically; there's no need to do anything other than have the mod in your inventory when accessing the Weapon Bench.

Thank you.