Hi I had same problem with my 2001 Discovery Auto , I removed fuse box compartment cover by removing 8 small bolts which fix in to metal rail also on left side undo bolt that fixes ito L shaped bracket .Next remove plastic vent next to matrix (On my car there is a bracket foot rest holding lower rail up ) remove all of these then remove centre consol there are 4 screws in side cubby box and 2 at front which screw in to lower part of dash once this is done you should be able to get to Matrix easily check to see if pipes from matrix to engine bay are all metal and that ends are not damaged be careful when you undo the 2 clips which clamp on pipes near matrix if you break them or they won't tighten up you will have to buy a new connecting pipe set as this is only way to get new clamps DO NOT TAKE THEM OFF OF REPLACEMENT PIPES AS THIS DISTORTS CLIPS ).It's difficult to get a tight fit if you leave pipes connected in engine bay so i disconected them and fixed other end first then refitted them afterwards top up check for leaks and hopefully job done .