My 96 Xj was stored in my barn for approximately 4 years because I was driving a company vehicle. While in storage the XJ reared I think 2 generations of squirrels in the A/C plenum. About a month ago I began hearing a "whirring" sound similar to a faulty blower mortor bearing. I pulled the blower motor yesterday and it bench tested fine. While I had access to the area where the "Squirrel" cage is I noticed leaves and other debris. I cleaned that out with a bent coat hangar and shop vac'ed it. I replaced the original blower motor and the "whirring" is still present.

My question is how do I get into the inner parts of the A/C plenum and vent tubing to get any further debris out of the system thus eliminating that irritating noise of a trapped leaf causing the harmonics? Thanks!