How to edit the form for student registration

I would like to know is it possible to edit a certain part of the form for student registration form in gibbon?
For example, I want to remove the star sign for email part to change the email from required to unrequired.
This is because some students and their parents do not have email.
Can anyone help me with this?

Thank you.

Hi Aoyama, you can do this by looking at /modules/Students and then editing applicationForm.php (which is the interface) and applicationFormProcess.php (which is the backend script that processes the inputs). However, any changes will be overwritten when you upgrade Gibbon, so be careful to record your changes. Good luck!

Thank you for your fast response. I will do as per your instruction.
Also, thank you for your reminder.