You can use the VPCART administration to edit your language values.Just go to Advanced Settings > International >Language >Edit Language.
You can then search for the caption or the language keyword and make the change by clicking the Edit button next to the record you want to change.
Note: If you wish, you can change the language values in the original language files (e.g. shop$language_english.asp and shop$language2_english.asp) and then re-add them using the Add Language facility. VPCART will add and update records as necessary.