Degaussing coils can sometimes be salvaged from old TV sets or computer monitors. The degaussing coil in one of these devices is usually suspended around the CRT.
If you can't salvage one, then make one!
To make your own degaussing coil:
1. Find a big spool of magnet wire, about 22 gauge. Preferably, this is a "found" spool of wire, paying for it defeats the purpose.
2. Flip over your stool. The magnet wire is then wound (loosely, so that it can be removed) around the stool legs until the bundle is a bit bigger around than your thumb.
3. Wrap a few tabs of electrical tape around the wire in places to keep the coil together, then pull it off the legs.
4. Strip the ends of the magnet wire and solder them to a line cord. Insulate the connections with heat-shrink tubing or electrical tape.
5. Wrap the whole coil tightly with electrical tape. Install one of those in-line power switches in the cord at a point that is easy to reach with one hand while you hold the coil on your other hand.
You now have a degaussing coil.
Plug the coil into an outlet and go to the CRT in need of degaussing. Turn the coil on and move the coil around the CRT as if using a magic wand in a circular pattern. Start with a small circle and then slowly expand the circle as you back away from the CRT. When you get so far away that there is no effect on the CRT, shut the coil off.
YOUR CRT IS NOW DEGAUSSED!