Re: Stuck Lower unit '90 evinrude
What year/model#?
And just because this happened to me, I had all my bolts undone, shift linkage undone, and it still would not drop. I could wiggle it like you, but it wouldn't come down. I had to use a huge flathead screwdriver and pry along the seal where the LU meets the midsection. I don't think my driveshaft was stuck, but when I got it apart I ended up with about 5lbs of sand that was in the midsection. Last owner had obviously not taken care of it, checked the water pump, or anything for a very long time. The sand is what was holding mine together. It was so tightly packed in there I had to literally use a small screwdriver and scrape it away. Not saying this is your problem, but it does offer another issue, albeit unlikely, but ya never know.
I'd take everyone else's advice and make sure you have all the bolts undone. If you do, then start prying gently, but watch your feet. Once it breaks loose, it's coming down, and anything under it is going to be smashed. Mine fell into the ground, and literally just stuck into the dirt, standing straight up.