jep,
I am afraid that article is a little misleading. That is a very cheap and lazy fix for a problem that will likely reoccur.
These grommets (rubber seals?) harden over time and heat, and if they are old, they will never seal properly. The only sure fix is to replace them, which is not all that hard.
Keep in mind the seals for the R65/45 are a different part # than the bigger bikes.
To install them, you need to remove the valve cover, and then remove the heads.
Slide the cylinder partway out, but keep the piston and it's rings inside.
You can now reach the seals to remove them. Pay close attention to their orientation. They will only fit one way!!!
Put it back together.
It is good to have a torque wrench for putting the heads back on. Especially so you do not overdo it and pull a stud out of it's aluminum threads!
Also, personally, I would never go this far without pulling the cylinder all the way off (no big deal) so you could also replace the large o-ring that goes around the cylinder base, and the two small o-rings that go on the top two cylinder studs.
You are trying to stop oil leaks, right?