1. If you do not already have it, download Poedit
  2. Access to your FTP server
  3. Go to wp-content/YOUR-THEME-OR-PLUGIN/languages
  4. Download the .POT file
  5. Open Poedit
  6. Click on Create New Translation
  7. Select the .POT file you previously downloaded
  8. Select the language of translation, for example: French (France)
  9. Now you can either use CMD+F/CTRL+F to find a certain string and translate it or you can bulk translate the file using the Pre-translate tool. (Catalogue > Pre-translate > only check “Don’t mark exact match as needing work” > click on “Pre-translate”)
  10. Save the file in .PO without modifying its name (File > Save)
  11. Compile to .MO without modifying its name (File > Compile to MO)
  12. Upload both files (.PO and .MO) to wp-content/[YOUR-THEME-OR-PLUGIN]/languages/here or in wp-content/languages/[YOUR-THEME-OR-PLUGIN]/here