dont bother splitting the middle box from the blower, that way lies madness and knashing of teeth. simply remove 1 extra nut on the bulkhead and a plastic nut up next to the blower housing under the dash, then the entire airbox will come off the firewall. Also dont disconnect any control cables, remove the heater surround & knobs then unscrew the heater slider control box from the dash, pull that out along with the heaterbox.