Any guides for upgrading from 1.5 to current rev 3?

Ok...up until now I haven't upgraded because gallery 1.5 did what I needed, but suddenly I'm getting thumbnail errors and other headaches that I can't resolve (yes I upped the max filesize in php.ini with no luck).

So my question is...has anyone else done this and documented it? I assume there will be quite a leap with 1.5 to 3 with the introduction of SQL (part of why I avoided it). I host my own site on a "slice" so I have root and can do most anything, I just lack knowledge for this task.

Thanks for any advice. I don't care if I lose comments, all I care about are the pictures really.

Dennis

www.dennnisjudd.com/gallery