It sounds like you have been reading the instructions for one of our older servo controllers instead of the Maestro User’s Guide. The Maestro servo controllers all support the Mini SSC protocol, but they do not require a special “mode”, and all configuration is done in the Control Center.
The section on Channel Settings describes the parameters you need to know. Specifically, to get 180 degrees out of your servo using the Mini SSC Protocol, here is what I would recommend:
Expand the Min and Max parameters to go from 250 to 2750us and apply settings.
If possible, supply your servos with a very low voltage (e.g. 3V), just enough that they can barely move, so that they are likely to be too weak to damage themselves.
On the status tab, slowly drag the control for a servo towards each extreme of its motion, stopping as soon as the servo stops turning or if you hear it straining.
Set Min and Max to values within this range.
Set 8-bit neutral to (Min+Max)/2.
Set 8-bit range to (Max-Min)/2.
Apply settings, and try controlling the servos with the Mini SSC protocol.