From the "Start" key right click and search for 'ie6' (make sure "Tools, Folder Options, View, Show Hidden File and Folders is checked)
Double Click on Folder "$NTUinstall.... which is found in c:\windows"
Next Double Click on Folder "spuninst"
Next Double Click "spuninst.exe"
This will inform you that you are removing and returning to the previous version of IE.
It worked well for me, as I just went through it today and then upgraded to SP1.
Good Luck...