How do you replace the left tie rod? The inboard end threads onto the power steering cylinder rod. The right side has a flat spot on the rod to receive a wrench, but the left doesn't. Also, there isn't enough space between the axle and the tie rod to put a regular end wrench on the big part of the tie rod.
Not sure about a 555, but the usual way is to pull the cotter pin in the tie rod stud, loosen the castellated nut a few turns, use a lever to force the tapered stud out of the steering knuckle while you hit the knuckle with a 2 or 3 lb hammer. The shock distorts the tapered bore and with you levering, it will pop out. In 40 years of wrenching, I've never had to use a pickle fork to get a ball joint or tie rod apart. Once you have it loose, it should be pretty obvious what to do next. I've got a 5550, and replaced the tie rod end this way.
If it's a 4wd, use two large pipe wrenches, one on each side on the joint ball next to the cylinder, the left side goes counter clockwise to brake it loose I seem to recall. If the side with the wrench flats comes loose first, turn the joint until you can just get a wrench on the rod and tighten the joint back to the wrench. You have to bang on the pipe wrench sometimes to start them moving. Raise the loader up and secure the safety bar before you start to give you some room, the end of the rod with the wrench slot can get messed up from the wrench trying to come off if you don't tighten the joint back to it. The rest is like said above, remove the pin, loosen the nut, give the boss a couple of good hits to pop the taper joint loose. The joint and tie rod are sold as a unit on some machines. It a simple job but can be a bear. They make a wrench for this if you can find one, dealer item, and like said some are really tight, two pipe wrenches 36" with a pipe on both may be needed, don't have much faith in the special wrench until it's loose. You can tighten them back using the two pipe wrenches and some blue locktite.