The inner joint (that is attached to the steering ram) is the radial joint and that will probably be a Deere part, 90% sure on that and I think about 175 bucks each. I'm very careful to make sure the boots don't get damaged as dirt will eat them up pretty quick. Every few years I pop the outer boot clip and inject some synthetic grease in the joint with a needle greaser and put the boot back on. Easy to replace, expensive to buy. The outers come off with a pickle fork. I have Kubota's but the joints are very similar and that is what the Kubota joint costs, I know, I had to replace one after 12 years and 4000 hours. No aftermarket choice on that one. Time to bleed green...lol
The inner radial joint has a jam nut holding it. Loosen the jam nut and wind the joint out (it will have a threaded stud that goes in the steering ram. Before you do, break the other jam nut that holds the tie rod sleeve, the pop the outer end out of the planetary casting so the whole assembly is free (easier to break the jam nuts with the assembly still attached at both ends). Once the nuts are loose. pop the outer joint and wind the sleeve that attaches to the radial joint off (measure how much thread is showing first), take the sleeve and outer joint off, unscrew the radial joint and replace, using the old jam nut. Thread the sleeve down to your measured thread depth, put the outer tie rod end back in the planetary casting and secure, Tighten the jam nuts and you are good to go.