Howdy,PQ.
There are a bunch of little things to try,but an easy way is to take it to about 160�-165� internal.
Wrap double in foil and put it back in to about 185� internal.
Some folks like to add about 1/4 cup beef stock,apple juice,or even a little coffee to the foil.
Check for doneness by pushing your thermometer probe through it,or poke a two prong meat fork in the side and if it slides off when you try to lift it,its done.
If still tough,put it back in and check in another 5�.
When done wrap in a heavy towel and let it rest in a warm ,dry cooler for an hour or so.
Hope this helps a little.