I would take the trackpad out so you can finish screwing the adjustment screw through to the other side. You should then be able to thread in a replacement. You may need to use some solvent to break the seal if someone glued it, you may need some heat to heat up the case and screw, making sure nothing melts nearby.
I would take the trackpad out so you can finish screwing the adjustment screw through to the other side. You should then be able to thread in a replacement. You may need to use some solvent to break the seal if someone glued it, you may need some heat to heat up the case and screw, making sure nothing melts nearby.