Once you find out if your host allows you shell acess, here's some info... (copied from an email I wrote this weekend to another person who was moving hosts at the same time as me!)
I never had really touched anything like this in the past, but figured out the basics... I downloaded a program called
puTTY. You'll want to log in with SSH instead of telnet (there's a little ratio button to change them), and it works with IP addresses (what I used because my domains aren't all
the way resolved). The commands in it are similar to using a DOS prompt, and if you are comfortable with that, you probably can figure it out with Ben's instructions. To actually get to the db directory to run the db_upgrade from the instructions just do
cd to change directories until you get there. To run a list of what directories you have (like dir in dos prompt) type
ls (for list)
If you don't think you are comfortable with this, don't try it - I'd guess that if you get your host involved with the instructions, they might be able to do this quickly and then you wouldn't have to worry about messing something up!
Hope this helps a bit,
Kristine