Honestly it's a doddle. A long orange punch, an old chisel, a length of hoover tube, a pot of grease, an oven and a big hammer and you're away. If all goes well you'll be wobbling along , thinking you've overtightened the new bearings a couple of hours later.
As you're a fellow high mileager, Stiggy old boy,would you like me to post you my specially butchered, torque wrench friendly, headbearing adjuster socket?
3 Africa Twins/280,000 miles. If it's happened to one of mine, it's gonna happen to one of yours.....eventually.
1 Varadero/45,000 miles ridden (of 68,000 miles on the bike), it's all still new to me!