Need to pull a new hydraulic hose through a planter frame tube? Before you remove the old hose, if you've got a bucket of old, used hydraulic fittings, find a "coupler" fitting and use it to attach the end of the new hose to the end of the hold hose,
Need to pull an electrical wiring harness through a planter frame tube? The tried and true method is to tie a long piece of baling wire or light rope to the end of the old harness before you pull it out. That way you can use the wire/rope to pull the new harness through the tube. Even better than wire or rope is an electricians "fish tape." Tempered steel fish tapes slide more easily through and between other harnesses and hoses already in the frame tube than kinked and twisted wire or snaggy rope.
Having offered these suggestions on how to pull hoses or harness through planter frame tubes, I need to confess that my preference is to run new harnesses and hoses on the outside of frame tubes. You have to be careful around hinges and pinch points, but it's much faster and less frustrating than horsing around pulling things through frames. Big, 3/8" x 16" zip ties work well to hold them in place. So does good old duct tape, wrapped around the tube a couple times. Electrician's tape will hold for a while, but seems to loosen after a couple years....
Don't forget that on most planters, the nut on the left disk opener has right-handed threads. Some planters have right-handed threads on their left closing wheel axles, too.