Remove the trackpad assembly.

You'll need to swing the display open slightly to remove the trackpad.

Take care to feed the trackpad ribbon cable through the MacBook Pro's frame without snagging.

Be sure not to lose the six small washers (two circular and four rectangular) resting on the underside of the trackpad.

Make sure your new trackpad has a ribbon cable installed before reassembly. If necessary, transfer the old cable, or install the one your new trackpad came with.