About to Set it on fire (Plz Help)

[Crayfish]

So I have an 89 Maxum with the 5.0 mercruiser in it. Alpha one. Ive replaced coil, altenator, and powersteering pump all in hopes of getting it running before summer is over. Well the motor is solid now and runs good but all of a sudden my trim and tilt is giving me issues. It will go down just fine but I cant get it to come up. I am running ATF fluid in it. When I hit the up button the motor comes on and runs fine but the motor doesnt come up. Ive been told I need to bleed the lines. Could someone please tell me the proper way to do that? Also, after holding the up button for a while the motor will shut off like it gets too hot. Wait a little bit and it will run again. Any help is more than greatly appreciated as I just wanna go to the lake.