I just successfully upgraded from 10.04 to 12.04, and these instructions appear to be exactly what I want. However, for the life of me, I cannot find Thunderbird's tools menu to import my Evolution email.
I am using Thunderbird installed as part of the 12.04 upgrade, and the Thunderbird global menu package is installed. I checked. I cannot find how to indicate what version Thunderbird is other than it was installed as part of 12.04.