By default, model templates are saved under: %localappdata%\Infront Analytics\Xla\template\ in the different following folders depending on the type:
Estimates
Fundamentals
GPRV
Multiples
Quotes
Ratios
Customised models are saved in a similar structure but under a different folder:%localappdata%\Infront Analytics\Xla\template_user\
If you need to customise a model then you have to override the related Excel file under the template_user directory.