i forgot my passcode of my iphone 4 but how i should restore it

Hi. If you forgot it and device was disabled: Forgot passcode for your iPhone, iPad, or iPod touch, or your device is disabled - Apple Support

Turn off your caps lock - all caps is considered shouting and therefore rude.

Many will not read your post or answer if they know the solution due to the all caps.

What happened when you followed the instructions in the 'erase and restore' portion

of the knowledge base article that thunderzzz linked to? If there was an error message,

what is the exact complete wording of that error message?

Hi There,

If you have forgotten your Passcode for the device, I'm afraid there is no way to recover it.

The only option you do have is to restore your device via iTunes. This means you will loose all your data so I hope you have a recent iCloud or iTunes backup to restore from.

I hope this helps and Good Luck!

Restore your device from an iCloud or iTunes backup - Apple Support

That's how 🙂