I designed this simple headset press tool to avoid having to spend too much money on a proffesional tool that I wouldn use maybe once or twice per year. Hammer and a piece of wooden plan would do the job too, but since I have a 3D printer at hand, there was no reason to spend couple minutes in Fusion and print my own version that is equally functional as the pro tool.
You can see me using it in this video:
Additionally, you'll need a couple of larger spacers, M10 threaded rod and two nuts.
The author marked this model as their own original creation.