Update Assistance

Hi There,

I plan to do a lot of updating soon. I want to update Buddypress, Framemarket, Marketpress, and change over from Supporter to Pro-Blogs, so this means updating Multi-Databases, right? I also have a number of Buddypress plugins to update.

I have my site live, and no off-line version of it. Could you just briefly tell me the best way to go about this, for example where to start. I have Gridmarket modified somewhat, do I keep my version and update just Framemarket? Also I have a number of PayPal subscriptions on Supporter how do I keep these when I update to Pro-Blogs?