'98 Johnson 150 ocean pro . If I can't get the trim manual release vale unfrozen, I thinks I still may be able to replace the o-rings on the trim rods and leaky end cap. I have to find or probably make a spanner wrench for this. It looks like I may be able to remove the end caps with the trim rods extended since I haven't been able to fix the manual release valve.
Concerning the manual release valve I've read using hammer to impact the screw driver might work. Also some said to use a torch to heat the area. Seems like heat would be difficult because the screw is up in there a ways. I've thought about buying a cheep impact driver and trying it since the hammer and screw driver didn't work. I don't think PB blaster would get past the o-ring to free the threads. (I haven't damaged the screw yet.) It looks like I'm tempted to leave the manual release valve stuck close and replace the trim o-rings.
ANY ADVICE WOULD BE HELPFUL. I'll try to post if I have success.