Run the bight of the new upline under both straps.

Hook the carabiner around the tail. (Or start with the bight, either is fine.)

Now pull the part of the rope between the two straps up away from the body to form a secondary bight. (The slack for this comes from the tail side so that you preserve the length of the primary bight.)

Hook the carabiner around the part of the rope between the two straps. Pull that up at least a handsbreadth away (more is okay, too) from the body.

Grab the bight.

Hook it on the carabiner as well.

Make sure the carabiner is fully closed. If it is asymmetric, make sure the wider side is down and the gate is pointing down.

Add an Overhand Knot or Half Hitch to lock the lines of the hanger together. In this example, I will use the Overhand Knot method: Reverse tension…

…protect a loop with your fingers and run the tail around all the strands…

…feed it to those fingers…

…hook the tail…

…pull it all the way through…

…tighten firmly.

This line is now ready to be run up to the hard point.

Thus.