First put the BSB unit on a flat table and remove the 12 back screws as shown in picture (2) .....Then remove the screw from in the middle holding the plastic cover for the LNB....Undo the swivel mounting bracket....Unscrew the LNB itself and remove....Remove the front panel as shown in picture(3)... Next and this is the part you have to mark which was the top otherwise it will all go wrong on reassembly remove the 4 large screws holding the front plate and also the 2 screws holding the waveguide cover see picture( 4).....Remove and store all the plates and place all in the same way...Get the film with all the 256 elements on it and look at how the gap is not symmetrical its offset by a distance this is what causes one half of the system to be out of phase with the other and the result is circular polarization and no good for ATV use....The corner of this sheet has a nice piece of foil just the correct size to form a quarter wave stub that we require to glue with the wife's nail varnish (not mine) see picture (6) across the present gap....Measure along this part of the foil see picture (8) and find the central point then cut a gap the same as you had covered with a sharp knife.....Now by reassembling the whole thing back but making new holes through the different layers such that the new gap is in the center of the waveguide as before......G3RFL