Hi Jim,
The freelance option is no longer available. A certificate of release to service is now required for all maintenance. To issue this you have two options.
1. Start (or join) a 145 organisation, requires an exposition, some sort of QA oversight, SMS, training etc.
2. Start (or join) a Part M subpart F, similar requirements as above, but you're paperwork burden is slightly reduced along with the scope of work you can accomplish.
In addition, you would also need to hold the appropriate type or group approval on your licence (Group 2a/b or 3).