1.Turn off phone first.
2. Press Volume Up + Home key + power On together
3. After 10 seconds leave power key to enter in recovery
4. Select Factory reset/wipe data with volume key and confirm with home key.
5. Go to yes- delete all user data press Home key
6. Phone will reboot. All data will be lost!
Hard reset Samsung Galaxy Y Pro - B5510
Hard Reset will erase all of your data
All described operations you are doing at your own risk.