how often do you change fork/shock oil?

I'm thinking about tackling it myself, going to do just fluid on the forks and not do seals because I haven't had a problem with them yet. I'm right at 40 hours as a C class rider. I hope it goes somewhat smoothly.

Buy the proper tools, watch a few videos, have a clean, open work space and get after it. Forks are too damn easy. 

50hrs. I do the forks myself and do the seals only as necessary. The shocks I send out for new seals and fluid as they are impossible to do now with the needle to pressurize it and setting the piston height on the wps. 

Spend the $150 and convert the shock to a tradiational bladder and service it yourself. 

Feels like all I ever do is spend money on suspension.. so like all the time

Like most 25-30hrs for best performance…I just went almost 50hrs on my stock 24 350 shock, I usually have stock components serviced around 20hrs as I always heard the stock fluids are lower quality? I used to do my own stuff or have my buddy do it for me but seems like we were constantly buying new suspension tools, at least for the forks… I have used  Factory Connection for 20 years, they have a support truck that goes to most New England races and their support technician is a great guy that gets it done same day…while the suspension is out, the linkage, swingarm and steer bearings get serviced…. Good times…👍

20 hours front and rear 

IMO if one needs servicing more than the other I would say the fork oil would be safe to go double the life of shock oil. If you don’t believe me touch your shock reservoir after a Moto, WP shock bodies will get absolutely smoked in no time if you slack on servicing it. 

Is it a simple diy conversion on this shock ?

I’ve done a few kyb/ showa shocks which are quite simple but never a WP. 

Once a year for new oil and replace worn parts, so probably 25-30 hours. I drop my suspension off at the local Race-Tech tuner. I don't have the skills/knowledge for suspension. 

This video covers the 16-22 bikes.  23-25 are similar, but a little different.

The main things are you need a vice, a propane or MAP torch, and either a strap wrench, special tool, or pin spanner to spin the old can off.  I've done quite a few of them.  WP varies a lot on their loctite use.  On some I got them loose with just a good, big strap wrench.  On others I used the special tool and the can was almost crumpling because the loctite was so strong (and yes I had it hot enough!).  I ended up using two hands and both the tool and a strap wrench to get it off without damage.   You also need to be careful not to heat it too much and cook the oring if you intend to reuse it.  Another tip, remove the sticker from the can and clean well before heating it up.  That will give a strap wrench better grip on the can.

Appreciate that !

Thank you 

After a quick read it seems there are mixed reviews on the bladder conversion being a good option . If you don’t mind sharing what your experience has been I’d appreciate it !

I have a family member with a 21 TC 125 with a “ broke” shock … LOL…

I’m sure it just needs a rebuild but that was the description I was given . 
Thanks again , much appreciated .

As far as performance, you may notice the shock being a hair more supple on chop, but it is definitely not a huge game changer.  As far as ease of maintenance, it is a no brainer.  I replace all mine with a bladder kit on the first rebuild so that every other rebuild will be so much easier.  Don't need the special WP nitrogen filling tool (which is hundreds of dollars, more than the bladder kit), don't need to set the piston height, don't need a vacuum bleeder, etc etc.   One of my bikes I've done this on is also a 21 TC125.

So I did the task of changing out the oil in my forks and it actually went pretty well thankfully. While assembling the bike I went to set my comp/rebound clickers and I had found that one of the forks was set to the "hardest" rebound setting. May be a dumb question but could this have screwed up the rebuild? will I have to rebuild that fork again?? surely not right??

I also want to add that the rebound clicker works just fine it is not stuck