removal of completeheater blower assembly from chassis

[billc]

 Audi A3 2010 Technik.

 I need to get at the back of the assembly that holds the heater  fan unit on the passenger side . Ive had rats at the wiring and the damage is at the back of this unit at the point exactly where the wiring comes through the bulkhead - I cant get access from interior side of bulkhead  with this assembly in place , Any ideas how I can remove this ? Im having difficulties here

 thanks in advance 

Bill