Help Format internal storage permanently

[msaour]

I just need to format my htc one x+ internal storage (phone storage) permanently, so no one can retrieve or recover files and data? is there any steps to do or any software you recommand me with?
Grateful and really appreciate your big help fellows

 

[nicka3200]

Settings>Back up & restore>Reset phone will wipe everything back to out of the box state except for htc firmware updates.

 

[msaour]

Thanks Nicka, But I already tired those steps and with some hits I could retrieve some old photos and some old documents as well!

 

[TheAtheistReverend]

Here you are my friend:
Forever Gone