Laplacian

I realise this is old but there is some very useful info. I recently tackled this but made the mistake of starting on the inside (ie removing dash). I have everything out except the heater box is stuck. I have unscrewed the gasket plate but can't get the bloody thing off! I have spent an entire day stuffing around with screwdrivers/multigrips trying to pull the inlet/outlet hoses off but they wont budge! I also managed to get my hand around the back of the heater box inside the car and felt the hoses that go through the firewall from the inside but I assume they should come out with the box if I can get the engine bay hoses off? I'd appreciate any advice on how to deal with this as its the only thing keeping the heater box in! I'll probably put the dash back in soon so that I can actually use the car so next time I'll tackle the engine bay hoses FIRST...