Wiper shaft mods
 

The wiper shafts on my 39 sedan stick out too far. Electric motors were installed by someone in the past and I don't really want to tear out my very nice headliner to get to them to try to fix this issue. I've seen something on an ad for the motors that mentions cutting the threaded mount and shaft. Has anyone done this and can it be done without removing the motors? Also, only the motor on the left side operates when the switch is turned on. Can both motors be made to operate off the same switch. The one motor does not park when the switch is turned off. Is there a way to make it (and hopefully both motors) park?
Thanks in advance for any assistance.