How would you easily transition from IE6 to IE8?

I've heard enough bad mouthing about IE6 and I agree to it 100%. I don't use it mainstream at all but the reality is a considerable portion of the corporate world is still stuck with IE6. Wanted to see how one can transition from IE6 to IE8 without too much overhead?

Cross browser can be done on a single machine because it let you install all those browsers but Windows won't let you install IE6 and IE8 side-by-side. Wondering how one can deal with the migration as easy as possible.

Any tips?