Get it while its hot! (Or try to, the servers, as usual, are bogged.
To upgrade, do the following: (note: you can only upgrade using this method if you are already using Feisty Fawn)
Go to System -> Administration -> Update Manager
Hit the Check button to check for new updates to your current install (Feisty)
If there are any updates, hit the “Install Updates” button, this will install any updates for your current installation.
A Message should appear stating there is a 7.10 release
Follow the instructions