i'm not going to be rude and simply tell you to search, because you have atleast done that, but this has been put out in detail - scattered and in a single thread (multiple times).
(BES Admin Corner; the forum you posted in)
At the top right, click on "Search this forum" and type 'BES 4.0 migrate' as well as 'BES 4.0 move' and I'll guarantee that you find an abundance of threads that you can either copy verbatim from (I know that I've personally stated the steps) and/or gather information from multiple threads and compile your own list. Lastly, I'm sure that I remember reading a document from RIM on the subject, as well.
Oh yeah, someone asked the same question (or something similar) just a few posts down, as well - same topic, actually.
And yes, I know it took longer for me to write this than it would have if I simply put the steps, but sometimes we all simply need to learn to use the resources that are already in place.