Template based on Helix Ultimate, like any other template, includes .ini file which contains all of the English terms that we used: language\en-GB\en-GB.tpl_folium.ini

Step 1:
Install Joomla translation for your native language, make it active.

Step 2:
Change the filename keeping original template name, for example:
from: en-GB.tpl_NAME.ini
to: xx-XX.tpl_NAME.ini

Where xx-XX is a LANG-PREFIX, for example, es-ES – for Spanish (Español), nl-NL – for Dutch, ru-RU - Russian, de-DE - German, etc.

Step 3:
In most cases, you should translate selected strings (used on front-end) to your language and save them with native language prefix. Each translated string must always be enclosed by double-quotes. File (.ini) must be saved as UTF-8 without BOM encoding. 

The most important phrases are probably those:

HELIX_ALREADY_RATED="You are already rated."
HELIX_ULTIMATE_MONTH="Month"
HELIX_ULTIMATE_MONTHS="Months"
HELIX_ULTIMATE_DAY="Day"
HELIX_ULTIMATE_DAYS="Days"
HELIX_ULTIMATE_HOUR="Hour"
HELIX_ULTIMATE_HOURS="Hours"
HELIX_ULTIMATE_MINUTE="Minute"
HELIX_ULTIMATE_MINUTES="Minutes"
HELIX_ULTIMATE_SECOND="Second"
HELIX_ULTIMATE_SECONDS="Seconds"

Step 4:
Once the phrases inside the file are translated, you can copy your language file into your language directory using an FTP client.

Notice! Other phrases can be from different components as SP Page Builder.