It is of note that unlocking your iphone 4rm a particular carrier network is absolutely legal.. The process dou mite be quite complex, yet simple.. Bt it saves you from unnecessary problems associated with unlocking of iphones and expenses....
The first step is
1.. Check for your phone details through your phones imei number..on imeidata.net

2.. Of course if it's locked you should find out which network carrier it is locked to.. Eg...at&t, verizon, sprint etc and their particular countries... all dis can be gotten from the website imeidata.net...

3..one.. Den u check if your network carrier your phone was locked to offers unlocking..you can check this out at dis address... support.apple.com/en-us/ht1937. See if your carrier offers unlocking . Only your carrier can unlock your iPhone.

First, your carrier will need to process your unlock request. Then you'll back
up, erase, and restore your iPhone to unlock it. Contact your carrier and request an unlock. You might need to meet requirements to qualify for unlocking. After you submit the request to
your carrier, it might take a few days to
complete. Contact your carrier for the status of your unlock request
3. After your carrier confirms that your iPhone unlock has been processed, go to the next step

4. Plug your iphone to an internet connected Pc with an updated version of itunes.. Make sure a sim card is in the phone.. Then Back up and click restore phone..and viola ur process is complete...for more info on how to back up and restore your iphone visit the website ..support.apple.com/en-us/HT201252..

Well hope dis helps.. 4 general info regarding unlocking visit support.apple.com ..

If ur network carrier does not support unlocking.. Well I guess der are threads here on nairaland dat can help u...or u can simply search on youtube..

As for those whose iphone are locked to at&t US. Visit att.com/deviceunlock to begin the process..
Hope this helps u...thank you..