P38 rear Wiper drains battery

Hi everyone (thanks for reading)
On my 2001 P38 the rear wiper simply does not seem to have enough power to work correctly it gets stuck 1/2 way and then will drain the battery! if left in the non returned position.

Is there a simple way to disconnect this for now.? Where is this best done?
Do i order a new motor? are these easy to change yourself?

thanks in advance....