I'd try bending it first too, though I'd use neither a hammer nor a jack.
If you can get hold of a big pipe wrench, 36" or better, and some
aluminum sheet, 1/8" or better to protect the strut, tighten the jaws as tight as you can about where shown in the picture below, and get a 10 foot or so cheaterpipe and lever up. Or down from the other side.
You start closer to the
route to avoid putting an unremovable kink in the middle of the strut, which is possible to do if you were to start lower down where you have better leverage.
As you
work the bend out, move the tool gradually down the strut.
The
keel needs to be resting on the ground.
If you see some motion, you can consider continuing with the pipe wrench, or you can go to the scrap yard and get some 3/4" -1"
steel plate and cut and grind something to a better fit and use that. Or the yard might have a tool ready made.
That shaft looks hard up to the shaft log; it may not come out without 'relieving' that contact first, I'd go for it with the shaft in place, and then deal with the shaft after you're able to get it out.
That looks like a pretty long shaft, there's a slight chance that it's not even bent, or only slightly bent and able to be straightened, if
money is an issue.