Your original carrier provide a free unlock after contract end. Contact them. They might send an unlock code – try that first. If it doesn’t work, then you need the file.
Before diving into the unlock file, let’s clarify what this device is. e5577s-932 unlock file
: This is the safest method and involves using your device's 15-digit IMEI number (found by dialing *#06# or checking the sticker under the battery) to request an official unlock code. Your original carrier provide a free unlock after
Once the device is detected as a COM port, run the firmware update tool (usually an .exe file provided in the "unlock file" package). e5577s-932 unlock file