How to replace soft top motor without removing roof.
Removing z4 roof.
Pull this ring pull out by about 1 4 and turn it through 90 degrees and this will lock the hydraulic bypass valve in the open position this will then let you lower the roof by hand.
Momo1 officially a forum statistic.
At around 18 minutes when screwing in the hydraulic line bolts back into the motor tighten these two bolts up to manufacturers spec.
Here are some nice instructions with pictures.
Replacing the motor involves removing the entire roof assembly which is a fiddly and laborious job and is an expensive option if you are going to get this done at an indy garage.
If the screen latches do not unlock from the down switch you can remove the plastic cover at the top of the windscreen to open the latches using an allen key.
A replacement motor was a cool 350 plus a new housing and hydraulic repair kit bringing the total to 450.
I know how to remove the covers on the a and b pillars.