How to rename label of select field in Accounts Receivable?

Hi! Is it possible to rename the label of select field highlighted in the picture? I want to rename Posting Date into Implementation Date and Due Date into Invoice Date.

Yes you can,
change it in accounts_receivable .py and .js file.

How can I access those files? Where can I edit those?

I’m sorry, just a newbie on erpnext.

You can access file from following path.
/apps/erpnext/erpnext/accounts/report/accounts_receivable/accounts_receivable.js
/apps/erpnext/erpnext/accounts/report/accounts_receivable/accounts_receivable.py