AkDan,
I put my harness on at the truck before I go in to my stand. Once there, I attach the carabiner on my harness tether to the prussic knot on the "lifeline". As you climb up, just slide the prussic knot up as well. Step onto the stand and slide the knot up to where you feel a bit of tension pulling on your harness as you set down on your seat.
The prussic knot is tied with a loop on it for attaching your carabiner to. Quick, easy, and secure.
The lifeline comes with good instructions for its use. Cheap insurance to use this set up. Give you piece of mind as well if your not so good with heights. The older I get, the lower I hunt LOL
BP