How to access bearings on this headset?
I'm not completely sure, but those bearings look like sealed units.  They likely get replaced rather than serviced.

I would start by getting more information on the specs of your bike frame.  The manufacturer will have details about the size of the bearings, and should be able to show how to get into it further.

Your last resort is to take the bike into an LBS for a service, and ask if you can assist/watch.  Can be a great learning experience.



To remove them, you probably need a drift to push them out from below/inside-the-frame.



This goes through the bearing, the four legs click out, and then you tap it from below with a rubber hammer.  You will probably need a headset press to reinstall them, and maintain parallelism.