I wouldn't panic just yet. As noted in a comment to the other question, I don't think your results are quite final yet.

Assuming there is an issue, there's one way: sent them together into Canon for service. They may do this for free (Pentax did with my K10D), but may charge some (I wouldn't be surprised if they rule this as within acceptable tolerances for a $100 lens). They'll do the work on an optical bench and get it just right; if you send in multiple lenses, they can test the whole set and select the appropriate compromise (the camera probably doesn't have a way to remember different settings for different lenses, as a higher-end model would).

Other alternatives are:

• use live view and contrast-detect focus when critical focus is crucial.
• or, manually focus.
• learn to live with it; it's only a little bit of focus error and if you stop down a bit it won't matter.
• and, make sure to buy a camera with focus adjust as a user-accessible feature next time.

I wouldn't panic just yet. As noted in a comment to the other question, I don't think your results are quite final yet.

Assuming there is an issue, there's one way: sent them together into Canon for service. They may do this for free (Pentax did with my K10D, before Pentax started including a micro-adjust feature on their cameras), but may charge some (I wouldn't be surprised if they rule this as within acceptable tolerances for a $100 lens). They'll do the work on an optical bench and get it just right; if you send in multiple lenses, they can test the whole set and select the appropriate compromise (the camera probably doesn't have a way to remember different settings for different lenses, as a higher-end model would).

Other alternatives are:

• use live view and contrast-detect focus when critical focus is crucial.
• or, manually focus.
• learn to live with it; it's only a little bit of focus error and if you stop down a bit it won't matter.
• and, make sure to buy a camera with focus adjust as a user-accessible feature next time.