Changing electrical grid parameters from 1 phase (splitted) to three phase grid

Any ideas how to change this model with adding 2 phases and changing transformer type?

I need to change it to 3 phases, connecting it from Cable1 block with another 3-phase transformer to Meter1 and Neighborhood1 (which is actually 5 different residential load profiles from excel files).

Model and scheme is attached or can be downloaded from Fabian M. Uriarte website: https://sites.google.com/site/fabianuriarte/downloads

Many thanks