Need help with tilt

I have a 2000 60HP. Was getting the boat ready for spring use and noticed the engine tilt was "sinking", not holding.

I opened the tilt chamber to check the fluid level...it was fine, so I hand screwed the plug about 1/2 way...and then tighten the a socket...but the plug didn't tighten..it just spins. Won't tighten but won't unscrew back out. Since it doesn't tighten..fluid comes out now.

Can really use some helpful advise here. Did I screw the pooch here, or can someone walk me how to get the plug out. If I get the plug out, will a new plug solve the problem?

I know its my first post, but could you your help...thanks in advance.

[boats.net]

If the threads are stripped then probably have to replace reservoir.

Is this difficult? or is it easy to access the 3 bolts securing the reservior, and to replace the reservior & corresponding O-ring.