Ubuntu Geek published a guide about upgrading Ubuntu 7.04 to Ubuntu 7.10
Howto Upgrade Ubuntu 7.04 (Feisty Fawn) to Ubuntu 7.10 (Gutsy Gibbon)
The Ubuntu team is excited to bring you the absolute latest and greatest software that the open source and free software communities have to offer. This is Ubuntu 7.10, which brings a host of excellent new features. This tutorial explains how to upgrade ubuntu feisty to ubuntu gutsy including step by step procedure and screenshots.
Howto Upgrade Ubuntu 7.04 (Feisty Fawn) to Ubuntu 7.10 (Gutsy Gibbon)