Customizing the customer viewable text/messages displayed by the plugin is easy to do.
Please see the following steps:
Step 1. Open the plugin's (e.g "wp-eMember") directory.
Step 2: Find the language folder within the plugin directory (it will have a name of "language" or "lang").
Step 3: Save a backup copy of the corresponding language file (e.g "eng.php" for English) you wish to edit before you make changes, in case you need to revert back to the original file.
Step 4: Open the language file that corresponds to your language.
Step 5: Find the text you want to edit. The entries will look similar to this:
define("ESTORE_AVAILABLE_QTY", "Available Qty");
You only need to customize the 2nd argument. So in the above line you will customize the "Available Qty" part. For example, if you want to display "Available Quantity" then change it to the followoing:
define("ESTORE_AVAILABLE_QTY", "Available Quantity");
Do the same for all the lines in that file that you want to customize.
Step 6: Save and upload the new file via FTP to the language directory replacing the existing file.
All done!