I used to use a two-handed approach to loosen a router collet, as shown in the drawing, but this meant that I had to use the muscles in my arms and shoulders, and if the collet released suddenly, I could bash my knuckles or, worse, send the router flying off the table. Then one day I discovered that if I positioned the opposing wrenches so that I could grip them in one hand, I could loosen the collet easily just by squeezing the wrenches together with my hands. If the collet loosens suddenly, no harm is done. This trick also works for tightening the collet.
John Ross, Bethel, CT
Edited and Illustrated by Charles Miller
From Fine Homebuilding #238