One of the most dangerous things some hunters do is put up a ladder stand, attach it to the tree at top, then install a lifeline. This is the most dangerous part of putting up the ladder stand. There are a number of ways to do this and for the benefit of our newer hunters, here are a few examples. These are only suggestions as there are many ways to skin this cat.

If the tree is straight enough and without limbs. Us a climbing harness and a climber to the height you need the lifeline to be, then tie the lifeline in and come back down.
If you have no climber but do have climbing sticks. Use a lineman's belt and climb with the sticks to the height necessary. Then tie in the lifeline and come back down. In either case, if you have help, put the ladder against the tree and use above climbing methods to tie in the stand, as well as the lifeline.
If you don't have either available and have 2x the amount of lifeline available this video will greatly help.
Hunt safe today so you can hunt again tomorrow.
https://www.youtube.com/watch?v=PwHwb0xcPWY