How to repair valve guide boss

So as plainly as you can explain it, what's the best way to repair these?

If you’re trying to get rid of the crack....... I would spotface the guide boss down flush with the spring locator step.
Then drill and ream for a .502” flanged guide(like what most aftermarket aluminum heads have).
Then, after installation....... only the new flanged guide would be sticking out above the spring locator step.