The Original LRT 12 105 is a really beefy item. My local Main dealer were kind enough to let me loan it for free, you could try the same, as Wammers has said it is essential for this operation. I had a lot of problems because the previous owner had lashed this job up.
From memory I think I put 100nm of torque and then buttoned in up in 3 stages of 60 degrees, 60 degrees and then a final tweak of 30 degrees.
Oh and bought a brand new bolt to refit as well, I understand that the bolt stretches slightly to lock?