Hi, and thank you for your interest!
mysms is being translated using Weblate, a web tool designed to ease translating for both developers and translators.
If you would like to contribute to translation of mysms, you need to register on this server.
This translation is open only to limited group of translators, if you want to contribute please get in touch with project maintainers.
Once you have activated your account just proceed to the translation section.