You should be able to lock up the rear brake with 1 finger and little pressure on the lever similar to your front brake. Back bleeding usually works. I used a 50cc syringe and pushed the fluid into the bleeder on the rear caliper. That removed all of the air out of the line. Rekluse recommends removing your rear wheel and pushing your rear brake piston all of the way in, then back bleeding. There is an instruction manual on the Rekluse site under discontinued products that walks you through the process.
Rekluse used to sell a clutch eliminater kit. They can still make you one and ship it to you for cheap. It is a banjo bolt attached to tubing that you use at the clutch slave cylinder. You fill up the tubing with 3" of clutch fluid and fold over the tubing then ziptie it shut. This provides enough fluid and minimal pressure to the slave cylinder so that the auto clutch engages properly.
One thing to consider. I just rode a very techical, VERY STEEP ride on Monday. Because my stock clutch MC is on the small side, I boiled over the fluid on the many long steep vertical drops. Not good to loose your brakes in these conditions. I am going to order a Brembo unit which is larger than my Magura. The AJP unit is much larger than the Magura, so it should not be a problem.
Hope this helps.
LHRB is simply awesome! I don't think I will ever go back!