He used an old-school EFS professional tool. He didn't just want a "placeholder" IMEI; he needed to restore the original, genuine IMEI from the device's sticker to ensure the network fix was permanent. He injected the IMEI into the modem partition.

He downloaded the specific G925TUVU6FRD1 combination file and the matching U6 stock firmware. He found a custom Engineering Boot file designed to bypass the secure boot check for rooting on this specific binary.

Using Odin, he flashed the Engineering Boot file . The S6 Edge booted up, slow and buggy, but rooted. With a rooted device, he now had access to the system partition.

The phone booted up. The T-Mobile logo appeared. The technician held his breath. IMEI Status: Valid.