I'm not a fan of tailgates like that sorry monza.
I want the peice that goes along the top of the place smoothed over. keep the plate there, but loose that peice and the lock.
Logie, removing the wiper is piss easy.
remove the plastic cover. on the inside. remove the cap on top the arm. remove the arm (nut on top). inside the tailgate remove the 3 bolts that hold the motor in. unplug the motor. should all drop out then. you'll need a grommet to fill the hole!