For the last 15 years I have always groaned when having to remove a bit
from my P-C 690 router. I always put one wrench in my left hand on the
bottom nut and the other wrench in my right hand on the collet nut. To
tighten was easy - simply squeeze the two wrenches together as if they
were pliers. Worked very well, but loosening was always a challenge
because I had to pull the two wrenches in opposite directions which
exercised muscles I used infrequently and really did not care to bulk up
on.

Lo and behold this weekend I made an amazing discovery. Simply reverse
the wrenches making the top wrench in my left hand and the bottom wrench
in my right and squeeze just as if I was tightening and the collet would
open like a dream. Where have I been and why was this not so obvious to
me?? Talk about a lack of brain power ...