I'll try and do another step-by-step over the weekend, time permitting.
From a project point of view, just link to the lib with the new name. However, there are code changes that need to be made also, these are all described here:
http://cegui.org.uk/docs/current/porting6to7.html There's a lot of it, but most of it will not apply to all projects - it all depends on what exactly you're doing and the facilities you're using. Probably the most important thing is to use the CEGUI::OgreRenderer::bootstrapSystem function to replace the current initialisation code to create the renderer and system objects.
Also be aware there a bugs galore in the 0.7.0 release packages, fixes are being made by the hour and we intend to issue 0.7.1 in early October to address the majority of these issues, if you're able to use the stable cegui_mk2/branches/v0-7 code from SVN it's highly recommended (and essential if you need the fixes before we can issue the 0.7.1 update).
CE.