Going from 2.3.x (Gingerbread) to CyanogenMod 7.2 (Gingerbread) is surprisingly simple unlike upgrading from Froyo. I’ll go into more detail below, but there are two necessary bits: an updated recovery rom and a custom (non-official) CyanogenMod rom. This version of CyanogenMod is specific to the Samsung Gio.
Before upgrading your Samsung Gio, you must first be running at least 2.3.x (Gingerbread) before continuing because of the use of ext4 instead of rfs. Please follow my upgrade guide “Upgrade Samsung Galaxy Gio from 2.2.x Froyo to 2.3.x Gingerbread” first.
Warning: Caveat emptor – While I used to this process to update my phone, I take no responsibility if you brick your phone. Be sure to back up anything you wish to save, this procedure works best when your Gio is fully wiped of data.