I was finally installing my f90bt today and I realized that there is a wire harness of another vehicle soldered on with some plastic cover over it. I don't have a soldering iron. Should i buy a new power plug or is there some way i can remove it to attach my wire harness?

Wire cutters, scissors, whatever.

Cut off the harness you don't need, attach the one specific to your vehicle.

Let me ask though. You got as far as installing the f90 without realizing that you hadn't attached your vehicle specific harness because there was another attached?

Really?

i was in the process of installing it. i have never done anything like this before and when I got it, i didnt know what everything was. today when i was installing it and i had all the parts and actually took out the stock headunit, thats when I understood that there was a wire harness on there and that it wasn't actually part of the system. sorry im trying to learn