Label Editor for VTiger was designed to change any label/element in VTiger. It supports fields, modules, buttons, menu items, lists and much more! Very easy to use interface (pick language, module, search and edit labels). It has a built-in search to locate any labels that are not as obvious.
How to Change/Rename Field labels
Go to Menu > Settings > CRM Settings > Extension Pack > Label Editor.
Select your input language.
Select Module file you want to put changes in.
It will show all the Variables and from there you can change the Labels.
Click on “Edit” button and enter the new Label.
The First/Last Name field labels are changed to Customer First/Last Name.