Prior to you could apply these directions it’s important to have a jailbroken iPhone and it’s a must to be on the 04.26.08 baseband(modem firmware). Which means that you have to be operating the three.zero firmware and have used PwnageTool, RedSn0w, or PurpleRa1n to jailbreak. YOU MUST ALSO (FOR THE TIME BEING) HAVE ACTIVATED YOUR IPHONE WITH AN OFFICIAL APPLE CARRIER. NO HACTIVATION SUPPORT YET.
To seek out your firmware and modem firmware(baseband) variations you could apply this tutorial.
If you are on T-Mobile or any carrier without 3G remember to turn it off before starting…
Step One Press to launch Cydia Insta
ller from your SpringBoard.
Step Two Press to select the Manage tab at the bottom of the screen.
Step Three Press to select the large Sources button
Step Four Press the Edit button at the top right of the screen.
Step Five Press the Add button at the top left of the screen.
Step Six Enter http://apt.geohot.com/ as the source url and press the Add Source button.
Step Seven Once the source has been added press the large Return to Cydia button.
Step Eight Press the Done button at the top right of the screen.
Step Nine Press to select apt.geohot.com from the list of user entered sources.
Step Ten Press to select com.geohot.purplesn0w from the list of packages
Step Eleven Press the Install button at the top right of the screen.
Step Twelve Press the Confirm button at the top right of the screen.
Step Thirteen After installation completes successfully press the large Return to Cydia button.
Step Fourteen Now press the Home button then power off and power on the iPhone. You do this by holding down the power button for 3 seconds then moving the power slider that appears to the right. Press the power button again to turn on the phone.
You should now be able to insert the SIM of your choice!