A basic QCN backup/restore tool (like QPST) is not enough when you need to individual NV items. That requires a specialized QCN file editor that can parse the binary structure, display readable values, and allow safe modifications.
Editing a QCN file is a high-risk activity. A corrupted file can permanently "brick" a phone's cellular capabilities. Furthermore, changing an IMEI is illegal in many jurisdictions. It is standard practice to always create a raw backup of the original QCN before attempting any edits. enable Diagnostic Mode on your device to begin the backup process? qcn file editor tool install