Hi @rgomez72
I believe you can do it by using .po (and .mo) files. Those files are usually used for translations but can be used in your case also. Files in question are located in >>wp-content>plugins>woocommerce-pdf-invoices-packing-slips>languages folder. Inside this folder you will find files named “woocommerce-pdf-invoices-packing-slips-[language code]_[country code].po” and “woocommerce-pdf-invoices-packing-slips-[language code]_[country code].mo”, find the one matching your WordPress language setting. If there isn’t exact match for English you can use “woocommerce-pdf-invoices-packing-slips-en_AU.po”, this one is for Australia and has only two lines “translated”, both for renaming VAT to GST. Use POEDIT software to edit .po file, change all items to your preference, save edited .po file using above mentioned naming convention, compile .mo file from inside POEDIT and upload both files to your website into mentioned languages folder.
I hope this will do the trick for you.
Regards,
cybland