how to pull pin holding bottom of tilt piston

[fishon401]

trying to disassemble tilt trim unit of 225 4 stroke but cant get pin that holds bottom of tilt piston to subassembly. I pulled the snap ring, soaked with penetrating oil and banged on the pin, but it wont budge. Anything I am missing here? How hard can I bang, Im afraid of breaking the aluminum.

[boats.net]

If it's freoze up that much probably have use heat to remove.