Chosen Solution

I just replaced the keyboard, and the screwdriver heads I used for taking out all the parts necessary for it, didn’t work for unscrewing the trackpad.

We don’t have a 15” guide on taking the trackpad out but we do have a 13” which is the same procedure MacBook Pro 13" Retina Display Mid 2014 Trackpad Replacement You’ll need a T5 Torx Screwdriver I’ll warn you the screws have thread lock on them so you will likely need some solvent or apply some heat to soften it.