200 HP Saltwater series II Trim cylinder cap stuck

Hi there! So, an easy job (by the looks of it, at least) has become quite a bit of a nightmare for me. There is a small leak on the seal on my RHS trim. I got the parts and watched all the videos. BUT... I couldn't get the cylinder cap to move even by a millimeter! Am I missing something? I tried opening the manual release as well. But, it too wouldn't budge! I already slightly gouged the cap holes and not keen on damaging it further. My mechanic friend gave me a tip to heat it up a bit with a heat gun or a blow dryer. Any help to loosen the cylinder cap would be appreciated. Motor is year 2000 L200FETO 2 stroke.

Air chisel or a large chisel and BFH (big F-ing Hammer)

You should purchase the piston kit. comes with each piston and gland nut. The piston gets pit marks on it and ruins the seals.

First get the right tool for the job.
It requires a spanner wrench.
I bought the wrench for $45
Just make sure to order the right one.

Then heat and a lot of it.
You might scorch the paint

It looks like just the seals gone bad.
But look real close after removal, the mating surface, if it has ANY corrosion
the cap needs to be replaced.

As said above put in vice and heat , if you don't have air chisel, 2 people with hammers and punches. Dont worry about damage to cap. You can buy cap,shaft and piston with all new seal as a assembly.