Even though I deactivate the fpt, it shows up anyways in game. I need it to be deactivated so I can properly sell it.

You have to go into your customs folder and delete the file for it

Really? That seems a little complicated for something like that. ._.

I am not sure where that folder is.

here you go this is what it should/would look like on windows

C:\Program Files (x86)\Steam\SteamApps\common\Toribash\custom\weoow eoo

you can just copy and paste that into the bar