Hello Evripidis,
I guess you want to remove the Cap to take out the springs inside of the fork-tube?

If it is so, remove the Steering bar to get enough space. Be careful , so that no Brake fluid escapes from the reservoir and perhaps damage other parts, e.g. your Fuel-Tank.

To remove the Caps it self you will need
 - a small Screwdriver with blade end, /(for slotted screws),
 - a Wrench Nut which fits to the Air Valve hex, and a suitable tool to get more distance for better workspace.
1. Take the wrench Nut assembly onto the hexagon socket of the air Valve
2. Puch down the Cap, enough so that the circlip inside is fully visible.
3. with the Screwdriver you can level out the beginning of the circlip. But be aware that the circlip is not jumping away. It it difficult to find it.
   It is a little bit tricky, but it will coming out.
4. Now let the plug (Cap) coming out by releasing pressure. If the Plug is not coming out at the first time, try again to push the plug into the Fork Tube and than release the pressure of holding down immediately. If necessary try it several times.
Reason could be some dirt inside, or a little bit of deformation of the grove of the circlip.

Regards Anja

Hello Evripidis,
one  at first. My Description belongs to the removing of the Fork-Tube-Caps (Imags No: 15/38) with the Air valve in it.

Do you want to change the Oil seals of the Fork?
If you want to go ahead with your scheduled Replacement, be aware not to scratch the inner Tube !!!

Primary, it would be better to take the Front Fork Units out and fix them on your bench.

I have attached to images with parts of the Fork Assembly:
8 /31 = Dust Cover
4/27 = Circlip of the Oil-Seal
3/26 = Oil-Seal

Regards Anja