Freelander TD4 Clutch Problem

Hi. Like many other members on your forum, I am experiencing problems bleeding my Freelander TD4 clutch. After driving the vehicle for four years without any clutch pedal issues, the pedal suddenly dropped to the floor. After speaking with other owners and several mechanics I concluded that the master cylinder was the problem. I have since fitted two replacement units. The first one was supplied dry and after fitting and several attempts at bleeding without any success I bought a second unit that was pre-bled and fitted that, but the result is the same. The only way I can get any sort of pedal is to reverse bleed the system and then I get about half a pedal. There must be a special way if bleeding this system, does anyone know what it is. I have been told that it has to be done with a pressure bleeding system, but can't see how you would get it onto the master cylinder as there is so little space above it.
Help please!!