shift cable stuck

HI, My '89 Sea Ray has been in storage, outdoors and covered, for three years. I'm about to do a major engine overhaul. Current problem is with stern drive removal. I know I'm supposed to shift lever to "forward" first. The cable seems to be stuck. Will travel no more than 1/8". I separated it from the linkage and have tried pushing/pulling cable by hand. No good. Had a friend spin prop. No good. Stern drive comes loose but only about 3/4 ". Can the rear end of cable be accessed in any other way? Thoughts anyone? Thank you. By the way, it's a 5.7 liter with an Alpha One drive.

Take the cable completely apart on the top allowing the center of the cable to come off with the drive. Never had an Alpha with a stuck slide. Change the cable when you get it apart.

Remove the lower unit first, then what gear your stuck in dosent matter for removal of the upper unit.