Somehow, you've partially disassembled the trafficator in situ. Never seen that done.
Anyway, I've only done adjustable steering wheels. There should be 2 small set (aka 'grub') screws on the backside of the hub. Remove these. For an adjustable, remove the brass not on the end of the steering box--have rags or a pan ready because you'll lose some/all of the steering box's oil--then disconnect the wiring. Bundle the wiring with some tape then gently pull the trafficator out from the cockpit.
If it's not adjustable, you probably have to remove the stator tube after removing the brass nut and olive (but you won't have to pull the wires through).
Once you've removed the trafficator, it will be clear what you need to do. The adjustable hubs have a circlip, I believe the non-adjustable have a big nut that has to be removed. Then, the wheel should slide rearward, unless the splines are gunked-up or rusty. Then, penetrating oil, soaking and some gentle persuasion should do it.