Yes you should be able to un-install IE6. The windows installer should have 'saved your previous configuration'. at least it did with me.
Once un-installed try to CUSTOM re-install and choose which bits you want and which bits you don't.
I, for example, have ZERO interest in MS Messenger, and am pretty happy with the Windows Media Player (version 7) that O already have on this (work) PC, so saw no reason to get them. If you are desperate for WMP9, then I suggest that you get IE6 and OE6 installed as a package, and then add WMP later.