I strongly believe that song lyrics should never be changed. They are just words and only hold as much power as people are willing to give them.
Some songs should be lost to history and probably forgotten, sure... but only ones that come from a place of hatred or actual malicious intent. No Green Day song even comes remotely close to this, in fact any of the songs with "controversial lines" that the band has written have only come from a place of positivity and desire for betterment.
In short, don't make a big deal out of words, especially those that come from a place of positive intent. If people are too ignorant to be able to tell what the lines actually mean, then it's no ones fault but their own and no band should ever have to change anything about them to cater to those people.