How do i apply the ingame weapon mods to a weapon?

[Sleepytime]

I just bought two weapon upgrades for my Service Rifle but i can not seem to figure out how i apply them to the gun, help please! :)

[erszebet]

Find your weapon in the inventory

press the "mod" button

job done :I

 

It's basically the same as repairing from your inventory screen.

[Sleepytime]

Now i see it, thank you!