Not able to change it from studio. From where it will change?
If you use SpiceCRM UI Studio is of no help.
Use language manager in UI workbench to create your label.
If you ovewrite an existing label, then it’s done. Reload page.
If it’s a brand new label, use fieldset manager to allocate your label to the field. Make sure you turned on workbench editing by setting
$sugar_config['workbench_edit_mode']['mode'] = 'all'; //possible values none | custom | all