The steering bearing is quite easy to replace. But you need to heat the headstock to 100C. Then the old bearing drops out easily. Get it back to 100 before dropping the new one in. IIRC there is a circlip.
When stripping it out, you need to heat the spindle pin retaining nut to soften the factory threadlock.
Don’t trust the grease it’s supplied with. Pop off the seals and pack it with grease. It’s not a rotating bearing so over filling won’t do any harm and makes it less likely to run dry in the ahead position.
When I did mine I also removed the rocking ball widgets for the fork legs. Cleaned and greased.