Saving Old Seagulls

hi all i need some help
i just recieved a seagull s/n sjp186k5. the piston is frozen. i'm starting to disassemble it so i can free up the piston.
i've read a lot of posts and looked at a lot of pictures. i have removed the gear box. i have removed the drive shaft. removed the screw that holds the water tube and the 2 nuts that hold the drive shaft tube. i see that the water tube has a fitting at the head. my question is how do you get the tubes off the motor. is the water tube just laying inside the housing ? i've tried tapping on the lower unit with a hammer and block of wood, but it doesn't budge.

Dalliance-
I'm not sure what you are referring to as "the screw that holds the water tube." There is a single small screw which holds the exhaust tube in place, which, when removed allows you to slide the exhaust tube down and expose the water tube and it's compression fitting at the cylinder. Undo the compression fitting, and with the exhaust tube separated and the drive tube nuts removed, you can lift the power head clear of everything. The exhaust tube and water tube can then simply be pulled free of the lower unit.

thanks todd
i am new to the seagull and am still learning the nominclature of the parts. the exhaust tube wouldn't budge. i had to remove the lower unit and use a drift pin and hammer it off from the top the lower unit that is inserted into the water tube. it came off with a little bit of a fight but it did come off. havwe since odered all the manuals so i can be on the same page as the rest of the world

thanks
todd

greg