you can build a var 30 like tool from the hardware store
it has worked well for me. also I like freeze-off and it helps to whack what ever tool your are using to add some shock, this tool allows for adding leverage easily
from sheldon
https://www.sheldonbrown.com/tooltips/bbcups.htmlThe tool is an imitation of a $40 shop tool that fits into the fixed cup as a crank spindle would, and pinches the cup. You apply unscrewing force to the tool, and it transfers this force to the cup with this tight friction fit.
The tool consists of a large bolt, a nut or two, and a few washers. The size of the bolt is not particularly critical, as long as the bolt is strong enough not to break, but small enough to fit through the hole in the cup. I used to use an ordinary 1/2-inch, 13 TPI hex bolt (also called a "cap screw"), which served me well for quite a while. It finally met its match on friend's Schwinn that had an unusually tight fixed cup; the bolt snapped in two before I could remove the cup.
Now I use a 5/8-inch 18 TPI hex bolt 1 1/2inches long, with a nut, a flat washer, and four lockwashers. The 5/8-inch size is the largest standard size that will fit through the hole in the cup. This bolt and nut both take a 15/16-inch wrench. With my 1/2 inch drive Craftsman six-point socket set, the 15/16-inch socket is also the largest size that will fit into a normal bottom bracket shell.
If you have some other brand of socket, check the fit before you buy the bolt and nut-you might need the next size down (9/16-inch).