How To Remove Pattern Lock Samsung I8750

1. Turn off the device,
2. Press the Power button for some seconds and then scroll down to turn off option.
3. Wait for 10 seconds to make sure that the phone is off. 
4. Press Volume Down key and Power key to turn the phone on.
5. Keep pressing the Volume Down key and release Power key.When the device boots with exclamation mark ” ! ” on screen release Volume Down key. 
6. Now you should press some keys in the following order:
   Press Volume Up key > Press Volume Down key > Press Power key > Press Volume Down key
7. After pressing the above keys the operation will start in a moment, So just wait for it to be finished.
8. Samsung I8750 Ativ Remove Pattern Lock.