HOW TO: Enable Cellular Data Network (GPRS/EDGE/APN) Settings in iPhone 4 on iOS 4.1

I have jailbroken iPhone 4 on iOS 4.1, I got it from carrier called Mobinil (Egyptian carrier) and then I changed to Vodafone Eg, so I was trying to find a way to change APN (i.e. Access Point Name), and finally i caught it, so that I will share this with you, I will show you a step by step guide to do this  on your jailbroken iPhone 4 running iOS 4.1

STEP 1: Go to Cydia and search for "Supreme Preferences 3.0" and then download it.
STEP 2: Now press on "WinterBoard".
STEP 3: Press on "Select Themes"
STEP 4: Now you have to select "Supreme Preference 3.0"
STEP 5: Go to "Setting" > "Supreme Preferences 3.0"
STEP 6: Now select "Applications"
STEP 7: Now select "Phone"
STEP 8: Now change "Cellular Data Editing" to ON
STEP 9: Now you can notice that "Cellular Data Network" has been appeared, press on it.
STEP 10: Congratulations, now you can change your APN settings according to your carrier.

Note: you have to this guide every time you restart your device.