Wecheling fork oil – hints and tips desired

Hello, I would like to wobble the fork oil on my scooter. I think I can find out that SAE 10 oil comes in there. And that the fork oil fill height is the following: Springed, without spring 75mm air chamber. So, and that’s where it starts. Does that mean that I put weight on the steering wheel so that it springs in, but is the spring inside away? Then it goes on: Can I change the oil at all without completely disassemblying the fork to itself / unscrew it off the scooter ? There is probably an Inbus screw at the bottom. There I can probably drain the oil, but where do I fill in new ones? Don’t I have to wash the fork rings anyway when changing oil? So I would have to disassemble the tele fork. And: Do I need special tools for this? Thank you in advance for the help. MFG PS: Roller is a JINLUN Star Quad JL50QT-5 with 50ccm and is a 4stroker