Day 4 started early I tried using 3/4" Fein electric impact wrench to open the bolt at the end of crankshaft. It did not move! Specs stated that it should have 750Nm of torque, but I think that rental machine was worn out and not having the power anymore. Well but at least I woke up the neighbours trying to open the bolt with the impact wrench at 7:20 am. But well.. head bolts on to make some progress.