The translation can be done with the Poedit program if you need to translate the theme-related parts.
Please, find your en.pot file from the folder themes/dfd-ronneby/lang. Open it in Poedit, generate .po for the language you need.
Check more details following the link to find how to create the .po file.
In this file, you can find the necessary words you need to be translated.
Translate the necessary phrases and then upload the new po. and mo. files to the folder themes/dfd-ronneby/lang.
Some more detailed information you can find here and there.
You can also use translating plugins such as Loco translate.
!Note, please do not forget to backup your language .po and .mo files.
