You wouldn't even have to replace the lower unit. You could just buy a new shoe if it came to that. I'd try bending the grates back as close as you can and then try the pins.

Sorry....shoe = lower unit, in a jet pump.

Merry Christmas......

Was surfing the net......found the following: Good information..

http://www.fishwithjd.com/2010/05/19/5-tips-to-help-improve-your-outboard-jets-performance/

I bent my fins up pretty badly last year and it was a beotch to get the pins out. I had actually compressed the hole the pin goes through and bent the pins somewhat and that coupled with the pressure of the bent fins had them stuck fast.

I spent a bunch of time straightening and wiggling the fins until they loosened up some and weren't presuring the pins so much. I then found a drill bit the same diameter as the pin and opened the holes back up a bit. Eventually, I manged to free up one of the pins and once one side was loose the other pin came out as well.

I think I used up my yearly allotment of expletives on that job.