It is, I have done it, but there are 7+ pages that need modification. It's a long process. What I did is take a field e.g. 'First Name' and search the downloaded bakery directory to look for files with 'first+name' in it (under Contents, not File Name), copied those files as back up, and amended as necessary with Notepad or Dreamweaver. These files with that search phrase all have the coding that relates to the contact form during checkout process
The files were:
view.php , view_form.php , view_summary.php , save_form.php , (then in /languages directory) EN.php , EN-GB.php , (then in payment_methods/paypal directory) post_data.php
To make it suit my needs for my site I'm working on, I changed 'First Name' to 'Your Name' and then changed 'Last Name' to 'Child Names' where relevant (keeping in mind the case and spelling) in the files needed. Uploaded them to overwrite the files that needed changing (including the post_data.php in the PayPal folder), and it worked fine. Studying the code to see how it is laid out (and I am NOT a programmer) allowed me to add extra fields as well.