TOZED ZLT T30S Network Unlock

I’m looking for a proven, step-by-step method to remove the carrier lock on a TOZED ZLT T30S so the unit can accept any SIM. The primary goal is to lift all network restrictions; I am not interested in feature tweaks or security bypasses, only a clean, reliable unlock... (Budget: $10 - $30 USD, Jobs: Technical Documentation, Troubleshooting)