How hard is it to change an EGR valve on a 2002 Ford Focus?

I was told by two different people it was hard, then another person said it wasn't bad, about a 45 minute job. Should I let my boyfriend (who has never done an EGR valve, but is very good with cars) do it, or send it to a shop for about 150 dollars? Also, there is some kind of sensor I think it is the mass air flow sensor, but I'm not sure, will that need to be replaced also, or only if it's bad. My egr valve is stuck in the same spot.How hard is it to change an EGR valve on a 2002 Ford Focus?
some of those parts are covered for 8 years under federal law/check with ford dealer service dept first or call their parts dept or ford factory service consumers affairs