We don't have a 15" teardown but the trackpad is the same as the 13" model. Here's the teardown so you can see its a very big job to even get to it: [https://www.ifixit.com/Teardown/MacBook+Pro+13-Inch+Retina+Display+Early+2015+Teardown/38300|MacBook Pro 13" Retina Display Early 2015 Teardown]