Write /Translations grid
The first step to translate a model is to create a grid in one of your excel files with the flag /Translations.
This grid should contain in the header the ISO 639-1 Code two-letters identifier of the language (https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes).
The first column is the language the model has been designed with.
Additional columns should contain the translated value of the first column.

Milliman Mind will try to replace everywhere in your model the original value by the translated value if it exists in the chosen language.
Change user language
User language preferences can be changed in the project manager.

Just click on your name on the top right corner > Change my preferences, then choose your favorite language.