If both the spindle and the chuck have some provision that allows the use of a wrench, it's your lucky day!

In some cases, you may need to use a thin wrench (or grind down a regular one) as there may not be sufficient space to fit a regular size wrench.

Unlike the retaining screw, the chuck is held on with a regular right-hand thread. Turn counter-clockwise to remove.

With the opposing action of two wrenches, even the most stubborn of chucks should come loose.