Yes, you need to remove it and yes there is loctite on it. Best way is to heat it up then you can break the loctite and reseal.

It's been a while since I've seen one but I don't recall having to remove the internal hex plug to repack the cylinder.

ok it's the mast cylinder
let me ask you this
is it leaking oil around the top of the cylinder where the ram comes out?
or, is it drifting down when raised up?
IF it is just leaking oil out of the top then you may can get by just putting new seals in the cap where the ram comes out.
But IF it is drifting down then there might be 2 things causing that, 1-the packing on the ram OR 2-the safety valve could be defective, all cylinders on masts have one, usually they are located inside the base of the cylinder or in some cases they are part of the inlet fitting depending on the design. The purpose is to keep the cylinder from dropping too quickly if a hose were to burst. Some call these velocity fuses.
From the sounds of it you already have the cylinder apart so changing the seals on the ram still may need to be done but if they aren't damaged you may can get by with what you have if you can't get it apart. If push comes to shove and you have issues with it you can always take it to a hydraulic repair shop and they usually can do all this for you.

Yes it's the mast cylinder I have a picture of the cylinder just don't know how to put it on here.... oh well thanks for the info!!!
Take care.
Kirk

i have seen some made that way, that would explain the hex hole in the end of the piston.
I'm going to make an assumption that this cylinder is one of the mast cylinders? those are the ones that are usually configured this way, the tilt cylinders generally have nuts on the end of the rod/piston end in most cases.

Thanks that's what I was thinking a loc-tote was probably used. I take it the piston has a male thread that is threaded in to the chrome rod

without knowing the model lift or having any sort of idea of the cylinder type this is a difficult one to answer. The question is do you need to remove that piston assy off the rod or not?
Some seals were made in some of those pistons in a way where you had to stretch them over the piston assy, usually heating the seals up so they would be flexible enough to stretch so they would not break.
If this is a case where the piston has to be removed though a little heat might be required to soften the threadlocker/sealer used to keep it from coming loose. Just be careful in heating, if you put too much heat it could warp the rod and cause problems after reassembly.
Note: all this information is just an educated guess since we do not have any model number of the lift or which cylinder it is.