On my Park tool for the Hollowtech II, you screw in the "dustcap" with a plastic thumbwheel gizmo at one end of the tool. I assume this is to provide you with something that you can get snug but not wrench tight. I just hand-tightened it with the thumbwheel as much as I could without pain and hoped that matched the torque in the instructions. So far, so good.
- Mark