When all of the suggestions didn't work, I wrapped some rubber around the watch case and held it in a vise so it was secure and wouldn't move. I got a automatic machinist !$$&* punch that has a sharp point and pushed on the end of the slide until the punch internal hammer released. The first impact moved the slide about 1/8 inch and continued to move about the same with each impact. After moving it about 1/2 inch, I was able to get it free by tapping it out with a small rod or nail. The aluminum case corrosion had occurred in many spots the length of the slide so it takes a snap force to free the bond. The sharp point on the punch is necessary to prevent it from hitting the watch case. I suggest that Vaseline be used to wipe the slide and groove and act like a sealant when installing a new slide to prevent corrosion from occurring from sweat and water.