Removing the blower motor housing

[ssbtech]

Trying to get a better look into the air box to see if I can trace a leak from the evaporator (and to clear out years of leaves and debris from before the cabin air filter retrofit kit was available) and I've run into a snag.  I can get the three fasteners off that hold the blower housing to the firewall, but the top bracket that hangs over the stud conflicts with the air duct serving the right side vent.  I figure I need to shift that air duct about 2/3 inch to get the housing past it.  

Any tips?  The service manual does not show dash removal as a prerequisite for pulling the housing down.  Can I move the dash panel up just enough to clear?  The manual does refer to a fastener holding the air duct down, but I can't see it looking in after removing the vent from the dash.

Thanks.