Customizing category/list names on Add Members UI pages for Champions Management Platform

I have tried using the Customization instructions in GitHub but have been unsuccessful. I'm not a developer/coder by trade, only by osmosis, so I need some help. Anyone out there that might be willing to assist? I would like to change "Region" to "Division" and "Group" to "Company" on the Add Member user interface pages.

[From my perspective, it would be great if we could change the name of the field in the SharePoint List which would then automatically update the UI pages. This does not change the underlying name of the field; only what the users see. Just like, when we change the "Title" or "Name" field in a list or library, the actual name for it (shown at the bottom of the Library/List Settings page when you mouse over the field name in the list) is not changed which, I'm guessing, is the name that is used in the programming/coding/commands and, therefore, wouldn't cause errors/problems when upgrading to new versions.]