1989 70hp Yamaha Trim issue

[brohloff]

Have a 1989 70hp 2 stroke. Has only been used once per year for last few years. Kept inside, dry, heated and like new but just not used much (I know bad for trim units).
Trim only goes up 6" or so. Has leaked some so suspect seals are out?
How does one check the fluid level? Where is the drain and fill hole?
Will recheck better tomorrow but thought will get some input b4 going back out.
Thanks
b...

[boats.net]

Raise motor up all the way(may have to loosen manual release screw) and remove the 17mm hex head plug and fill with power trim fluid.