NOTE: AWPCP now comes with an OFFICIAL Spanish (Latin American) version as of 2013.
To translate AWPCP's strings to your native language, OR to change the values of the labels for your own purposes, here is a set of instructions to follow:
1. In your WP dashboard under Classifieds > Settings > General, enable translations by clicking the box next to "Turn on translation file (POT)." Note: In some versions, it may say "Activate Languages" instead.
2. Download poEdit for your operating system here: http://www.poedit.net/download.php
3. Once in poEdit, go to File > Open... and find AWPCP.pot (in wp-content/plugins/another-wordpress-classifieds-plugin/languages)
4. Right-click on the field you want to change and choose "Copy original to translation field."
5. In the bottom box, change the wording to how you want it. For example, I changed "Item Price" to "Item Price (don't use a dollar sign)"
6. Repeat step 5 for ALL strings in the file or those you wish to change.
7. Save as AWPCP-<language>.po. It will automatically create the .mo file: AWPCP-<language>.mo, where language is your ISO country/language code, like en_US, fr_FR, de_DE, etc.
8. Upload both these files to the same directory AWPCP.po was in.
9. For non-English users, make sure your wp-config.php has "WPLANG" defined for <language>. Save the changes
Here are other resources and links you can browse as well:
Here's someone who recently made a translation into Hebrew and posted very detailed steps on how to get it right, quickly:
NOTE: Make sure you use the CURRENT version of default.po for this effort, not the link he suggests.
Furthermore, here's a guide for translating WP plugins in general (including language codes, naming conventions, and encodings):
UPDATE: There is also this Quick Start Guide article that details ALL of the places with strings you need to translate in AWPCP (not all are in the PO file, and that's because AWPCP is so configurable): https://awpcp.com/quick-start-.....-translate