The first step (which is more like a leap over the moon), would be to get the differences from the current ofono build (which is a fork that was maintained by Canonical at the time, and has quite a lot of changes from upstream) reconciled with upstream ofono, so we can upgrade to the latest version.
There are about 45k lines of changes between our ofono, and upstream 1.17 (which our fork is based on). This will require a lot of patience, and will require some knowledge about MTK modems and such, as we'll need to keep most of the changes from the fork when updating.