I've done it. More complicated than an front fork service, but not beyond doing it at home. I did not do a complete disassembly or try to revalve it. I simply removed, cleaned and replaced all the main moving parts, Teflon bushings seals and o rings. The manual I linked below from my Dropbox has you pulling every component apart, shock eyelet casting off the shock body for example, I didn't go that deep.
I called Ohins USA for the parts, they were very helpful and sent what I needed right out. About $70.00 in parts, but this was maybe 3 years ago. Shock oil (not the same as fork oil at all) is oddly expensive.
Only special tools needed were a spring compressor that I had, a tool I made to remove and install the end cap / fill port and measure oil level (just a small threaded rod and small vice grips) and the nitrogen charge needle to bleed pressure off before disassembly. Linked below is not the one I got, but very similar and about the same price. I did not buy or rent a Nitrogen regulator and cylinder. I went to my local Honda motorcycle dealership. The service department charged the shock for me while I waited for $10.00. I called to see if they could / would do it before ripping in to my shock.
Getting ready to go at it again. Feeling a bit harsh lately.
Is it worth doing it yourself? For me the hardest part was the nitrogen charge. If I wasn't able to have it done at the Honda dealer, 20 mins away and it took about 15 mins for the work, I might not have tried. The tank and regulator are pricey enough that if you don't already have them, it becomes more costly to do it yourself than to just send it out. Also, if you need or want re valving or repair work, maybe send it. Although Racetech might have a gold valve kit, I didn't look.