The windage drum on many AK's is frozen in place by paint and dried lube.
Apply a drop of CLP Breakfree, Kroil, or any good penetrating fluid to the ends of the drum, give the drum a couple of good raps with the butt of a plastic screwdriver and allow to soak overnight.
Try the adjusting tool again.
If it still won't budge, apply a LITTLE heat. DO NOT over heat, just warm it up to allow the fluid to penetrate.
If all else fails, get the front sight support WELL BRACED with wood blocks, and use a brass drift and a light hammer to break it loose.
Be careful to make sure the sight support is properly braced or the front sight can be knocked out of line on the barrel.