Software :: Step By Step Guide Required For Converting POP Gmail Account To IMAP, With Mail?

I've been using Apple Mail with POP Gmail for a few years now with problems. Generally I ignore the Gmail side of things and only ever access through Mail at home, and also use a Blackberry to send and receive emails.

At the moment Gmail pushes mail to my Blackberry and also holds it in the Inbox at Gmail until my Apple Mail app on my iMac downloads it, whereupon it's all moved to All at Gmail. This works fine, but is a problem when I use Mail on my Powerbook - once it downloads the new mail, Gmail moves it to All mail and when I get home and fire up my iMac's Mail, those emails won't appear there. Annoying. So, I need to go IMAP.

My problem is that as I have never bothered with tagging or sorting things on the Gmail side of things, and have done all my ordering through Apple Mail with custom folders and rules, I get the impression all that work goes out the window and I have to start over in terms of organising again, and that in fact any rules I want to set that I want to be duplicated across devices have to be done on the Gmail webpage. Is there any way whatsoever of somehow exporting my Apple Mail rules over to Gmail so that when I change to IMAP it somehow keeps things as they are as best as possible?