Clean Install 10.8: How to Migrate User Data?

Question

Hi,
I'd like to do a clean install of Mountain Lion 10.8 Server and migrate the user data, but I'm not sure how.
In specific for each user:
iCal calendars and events
Mail IMAP messages and folders
Address Book contacts and groups
And I think that's it
The data was originally set up in Snow Leopard 10.6 Server, but has since been upgraded to Lion 10.7 Server. I mention because I think that has bearing on the storage location.
I suppose I could do an Address Book export. I've attempted to re-import iCal before and the server ends up wanting to send calendar events to every invitee ever listed. I'd like to avoid that scenario again.
For Mail, could I keep the client-side IMAP folders as-is and then add the new 10.8 IMAP account to Mail before dragging over the whole folder structure? Or should I move it to "On My Mac" first and then do the same? Or is there a server-side way of moving the data store to the newly-installed server?
Thank you!

Answer 1

Thanks for your response. I'd read about that approach (a PDF on MacRumours descibing the process), but I'm wondering if I'll be re-introducing older Lion and Snow Leopard elements like folder locations and such if I do it this way.
Will ML migrate it to the standard location and treat it as though this data had been generated within ML all along?
Also, I should add, I'm doing this install because I pooched my Lion Server and had to restore from a Time Machine backup. Now everything is messed up and unreliable. Turns out Time Machine doesn't back up iCal events for users! So this is why I'm trying to do this as clean as possible.