You can do this in the field yourself. I've done it before by digging a hole and lowering the stick and bucket down in it so that the top of the boom and stick cylinder are close to working height from the ground. Make sure it's stable and won't buckle on you. Used a couple of good 4X4's and 3/4" plywood laid across the hole so we didn't fall in. As I recall, this model has a threaded head gland.
Remove stick end pin. Prop cylinder assembly up off boom with crib block. Suck rod all the way back into cylinder. Shut machine off and TAG OUT OF SERVICE!! Can't remember if this model has set-screws in head gland to secure it to barrel threads, but look and remove first if it does. Loosen the cylinder head gland, then the cylinder base-end hose fitting and drain oil into proper container and dispose of according to regulations. Remove head gland with rod and piston assembly. It's heavy and slippery, use a hoist and nylon sling. Remove piston retainer(s) and piston from rod. Remove old seals and o-rings from piston and head gland. You may have to replace the head gland wear bushing if it is equipped with one. Clean all three pieces thoroughly and check closely for other damage such as cracks and gouges. Check rod for straightness. Check cylinder bore for damage.
Hopefully everything metallic is in good condition. But it's a good time to replace the rod eye bushing if it's worn out. Get torque specs from dealer before reassembly. You may have to rent, barrow, or make a tool to obtain certain torques, but do not just use an air impact wrench to tighten retainers. Worst thing in the world you can do for final assembly.
Carefully reinsert rod into head gland and install piston and retainer(s). Do check to make sure piston is securely tightened to rod, again as close to factory specs as possible. Carefully install new seals and o-rings on piston. Push rod thorough head gland a foot or more. Carefully insert resealed piston and rod assembly back into cylinder barrel. Push rod and piston assembly a little ways into barrel. Very carefully rethread head gland onto barrel. Tighten head gland onto barrel as close to factory torque specs as you can. Reinstall set-screws if equipped. Tighten cylinder base end hydraulic fitting. Start machine and at low idle carefully run cylinder all the way in and back out all the way. Do this several time to eliminate air in cylinder and lines. Line up rod eye and re-pin with old or new pin as needed or desired. Check hydraulic oil reservoir and refill to fill mark.
Now, check base end pin and bushing wear. If desired, remove stick cylinder base pin and prop base end up on crib blocks. Replace base end bushing. Remove crib block and reinstall base end with old or new pin as needed. Grease pins and bushings. Remove plywood and 4x4's. Exercise stick, bucket and boom. Bury hole. Go get a cold one and congratulate yourself for a job well done.
All this said, you can hire a independent mechanic to come in and do the work, while you sit in the shade watching and quaffing a cold soda. You or he can remove the cylinder assembly as well and take it to a hydraulic re-builder in your area, or a Deere dealer. The last two will have a hydraulic bench that can easily remove and install the retaining hardware, and also make it easier to remove/install rod and piston assembly. You also get a warranty from the dealers, and you certainly want to ask an independent wrench buster to warranty his work.
If you take the cylinder off yourself, you will still need to make sure the boom and stick are secure and that you can safely work around it.
You can use a scaffold or the back of a truck for a work platform either way instead of digging a hole, but it's a bit more awkward and you climb up and down a lot, not a small consideration when you figure in the slippery footing from the oil you will spill. You will need a hoist of some kind for this.
Best of luck!!
