How to replace track pad on MacBook Proearly 2011

I would say follow the Teardown of the MacBook 17" from 2009 or follow the removal of the Battery in the Guides there are available. The Touchpad is directly accessible underneath the battery, or at least it should be. If the Touchpad is underneath a black cover, like the keyboard, then you should be able to peel it up safely.

The 17" model shouldn't have changed much from the yearly revisions, but the construction should still be the same: Touchpad underneath the Battery, secured with screws and a ribbon cable. Try that.