Abundance supports .po/.mo translation files. To use them please unzip the po file and open it with Poedit (http://www.poedit.net/download.php). Now translate all text strings. Save the translated text strings under following name "your-language-shortcut.po" . Assuming you come from Sweden save it under: sv_SE.po, if you're from Germany de_DE.po
A list of language shortcodes can be found here: http://codex.wordpress.org/WordPress_in_Your_Language
At least you must save/upload/copy the generated .mo file in your theme main folder.
Attention: Wordpress will only use the translation file if you set the right backend language: http://codex.wordpress.org/Installing_WordPress_in_Your_Language
Please upload your translated files (by using one click hosters like http://mediafire.com ) and post a link here. It will save other users a lot of time and maybe you'll get some feedback (i.e. suggestions how to improve your translation, etc.).
Default, untouched english po file - use it to translate Abundance to your language. You can find them in the "lang" folder (wp-content/themes/abundance/lang is the default path).