Lyrically Speaking

In general you don't have to change much in the song to avoid the copywrite laws. IE: Weird al Yankovic was sued for one of his songs, but won because the ending was differant.
As for the actual idea of trying to "dethrone" a band, most of the bands you find now are fast-food broke morons who did not work hard to get anywhere and only make it big because of declining taste in music. In the 80s America was the final frontier. Now we have people pop up over night. The best thing to do is ignore it all together, listen to bands that actually care, and if you play, be yourself.
(Wow...responded to both. Yay)