This took me way too long, and there is a trick, so I'm posting here where it
can be found when others need it.
I have an H-frame Enerpac 10 ton hydraulic press. The cylinder started to leak. So, the natural thing was to order a kit and fix it (this is not a Taiwan disposable unit, and anyway, the kit cost about $25, via Amazon.com. The specific cylinder was a 1010 (10 ton, 10 inch) and the specific kit was the Enerpac RC102K. To follow along, you will find the sheet below helpful - if that link doesn't work, search for document number L653 or seach for RC102K
here is the procedure, taking into account what I learned doing this:
1. remove inlet quick disconnect (17)
2. drain oil (into a container, not all over the floor)
3.remove saddle assembly (12) - it just pulls out or unscrews, depending on your luck
4. remove the nut that is under the saddle assembly (10)
5. use a screw driver to turn the slotted screw visible - you want to turn it clockwise (this is the side of screw 7 without the head) until it is inside the threaded bore of the piston (16). This relieves the tension on the return spring (15) Remove and recycle the copper washer
6. unscrew the return spring retaining screw (2) and use tweezers or a needle nose to get the screw out of the bore
7. unscrew bearing stop ring (13) using a suitable tool - this presses on the packing (AKA wiper) so it shouldn't be very tight
8. use a screwdriver or punch to press on the ring on the end of spring (15) to start the piston on its way out of the bore
9. use a rag to grab the pistonand pull it all the way out, catching the bearing sleeve as it comes out.
10. remove the four split rod bearings, (6) clean them and put them aside
11. remove retaining ring (3), cup( 4), and brass washer (5)
12. clean everything.
13 install new brass washer (5), new cup (4), new retaining ring (3)
14. put the split rod bearings in place, chamfer to chamfer, with the splits aligned 90 degrees apart
15. lightly lubricate the cup and pistonand slide the piston assembly about 3/4 of the way into the piston
16. slide the bearing sleeve onto the piston
17 slide the wiper (the black rubber ring) onto the piston
18 slide the stop ring onto the piston and screw it lightly into the threads at the end of the sleeve
19 align the ring at the end of the spring so you can put new screw (2) through it, and insert and tighten the spring retaining screw.
20. turn the slotted screw you turned in step 5 (screw 7) counter clockwise until you feel a good spring tension or the screw is sticking up about 1/4 inch proud of the piston.
21. place new copper washer (9) over the screw (7)
22 place nut (10) onto the screw and tighten until the piston starts to turn
23 tighten the stop ring to help hold the piston and tighten nut (10) some more
24. install quick disconnect inlet assembly
25. put repaired cylinder on press and pump it down and let it back a couple of times to get the air out of it.