Removing Hydraulic Lift Arms

I have heard how difficult it is to remove the hydraulic lift arms on a 8N, I want to replace my because they both have been welded. Is there one way better than another.
Thanks

I've never had a problem getting an arm off.. now.. getting the rockshaft out of the cover .. that's another story..

the usual stuff has always worked for me.

penetrant oil, beefy puller... heat if needed. air hammer / chissle to start stuff moving.

also, you can use a sledge hammer as a backup tool, and a maul or drilling hammer and then with the backup placed on the OD of the arm where it is onthe spline, hit the other side that is 180 degrees out, then work your way around as you can. this actually stretches the metal.

lastly.. if they are junk arms you don't need to save, and they don't come off with the minimum of hassle of your first try with the puller, then just take a die grinder or angle grinder and cut some slits in them down the length of the coupled spline area.. don't cut thru to the rock shaft just about 75%.. that itself usually loosens them up.. if not, wadge a wide cold chissle in the slot and split them, or employ that air hammer / chissle again.

Again.. these should IMHO, come off easier than driving stubborn knuckle pins out o fthe hyd lift arm linkage or even necked bolts out of axle halves for the radius rods.. etc.

Thanks for the infro, I really didn't know where to start on removing them. The old arms are junk so I think I will use the grinder as you mentioned.