I have read about this but can't find any instructions on how to do it. I even sent Ohlin an email last week, but no response yet.
It’s fairly easy, you’ll need some basic tools and a little fork oil. Ohlins of course recommends theirs but you can also use Fox Gold which is more common (ie more available)
Here’s the gist of it (you don’t have to remove it from the bike but helps if you have a bike stand.
Release air pressure from both air chambers
Remove the black nut on the bottom of the air side leg (~13mm or so).
- you will have some oil drain out of this so have a bucket or similar ready.
Use a cassette tool on the top side of the air chamber to remove the entire cartridge. When you unscrew this the whole air cartridge will simply lift up and out as one entire assembly.
You do NOT have to remove the stanchions from the fork lowers, leave them attached.
Once it is out there will be a blue anodized piece in the middle of the shaft, use an adjustable crescent wrench (I don’t recall the exact size, maybe 21mm or so) to unthread the blue piece. You’ll see it has flats on it for the wrench. I used a second wrench with the cassette tool on the opposite side to keep hold it while unthreading.
after you unthread it you can pull the blue piece down the shaft, and separate the main smaller diameter piston from the larger one. It will feel like a strong suction, because it is, to help you can depress the air release on the cassette tool side.
Here is the tricky part, not difficult just tricky.
Look down inside at the very bottom of the blue anodized piece, you’ll see a white plastic spacer stuck at the bottom, you need to carefully use a pick or something to slide the spacer up and out of the blue piece.
Once you manage to do that, the spacer is actually split, so find the split and use a flat screwdriver or similar to spread it apart and remove it from the piston shaft.
After that, reverse all the steps to put it back together.
When it’s assembled and you are dropping the complete cartridge back in the fork keg, I made sure the cartridge was mostly assembled and the fork stanchions were depressed into the lower keg. So basically the cartridge is sticking up out the top by at least a couple inches.
This easily allows you to re-secure the bottom black nut, add oil through the top directly inside the fork keg, then resecure the top with your cassette tool.
Add pressure (ramp up chamber first per manual) go ride and enjoy!
I wasn’t sure what I was gonna find when I did it myself so the first one took a little over an hour, I didn’t even know what the spacer looked like or if I really even had one haha, but it’s in there.
When I did my second fork on the other bike, it literally probably took me 15 min.
As with anything when you actually know what your doing lol.
Hope that helps, feel free to ask any specific questions.
The first ride last night was pretty good. Coil is going to take a bit of getting used to, but I think I'm going to like it. 
I have the ohlins setup on my stumpy EVO and SC Nomad. Still epic nonetheless and you’ll love it. I did EXT coil and custom Fox 38 with avalanche on the turbo levo.
. Work very well and is easy to set up.
