I preface with saying that I don't recommend this.
Most CRT's have adjustment knobs somewhere on the inside that may help. You'd literally have to remove the top cover and look around. They're often glued in place. Basically it's a factory adjustment system.
The problem with this is that it may or may not help your situation. On top of that, you really can't adjust them with the monitor off, and there's all sorts of high-voltage crap in there that you could give yourself a pretty good jolt.
So buy a new monitor.
