How do you unlocked my samsung sgh-c145 i forgot the password?

There are few different unlock passWords for T749.

If you getting "Phone Lock" passWord prompt you need to reset Phone Lock. This can be done by flashing your phone with any firmware. You will need MultiLoader software and firmware files. You will need USB cable.

If you are getting "Network Lock" or "Phone Freeze" you need to unfreeze and unlock code. This can be done by via USB cable but there is no free solution to make it. You can get software and instructions to read unlock/unfreeeze code at related links