Here's a procedure I stole from the net. May have been CTOCF. I used this on my FarmPro 2425. It's all done from the rear of the tractor. I don't know if the 354 is similar or not.
There's a picture from the parts book using the reference numbers (XX) that goes with, but I can't get it inserted into the post. Still trying to learn this new format.
3Pt Piston Repair Kit #GB3452.1-1992
Jinma 224 (30 min)
This will help you change the main seals in the piston under your seat.
1. Lift front of tractor eight or so inches off the ground.
2. Drain hydraulic fluid. The drain is the bottom left bolt on the rear cover
part #160.55.140-1 (46)
3. Remove rear cover
You will have to move the lift arms up and down part #160.55.013 (30) to remove
the following parts.
4. Remove pin 4×40 Part #GB/T91-1986 (35)
5. Remove bolt m8x12 GB/T5783-1986(32)
6. Slid pin over to the side Part #160.55.020-1 (33)
7. Remove the piston rod part #160.55.132-1 (27)
8. Insert a 5 mmx.08 screw welded to a shaft in the back of the piston part #160.55.130
(18) and pull the piston out
9. Replace o-ring 63×5.7 part GB3452.1-1992 (15) and the two plastic back up
spacers A63x2 part # GB3452.1-1992
10. Put grease on the o-ring and reverse the procedure.