How to make unlock factory server by IMEI

If you need to ask the question, it's probably not for you.

 

Basically you can't. To do an unlock on the server side you need access to the server. Those companies do what they do by having someone in the inside. The best you can do is buy it unlocked, wait out your contract and ask your Carrier for an unlock or jailbreak and do it by alerting the firmware.