So it seems that your Phone is locked with the 4-Digit PIN and if you do not remember/ are unable to inout the correct one/ disabled the device, the only way to get around this is to restore your device via iTunes.
However, to do this you will need to place your device into recovery mode: If you can't update or restore your iPhone, iPad, or iPod touch - Apple Support
From there it will prompt you to "Update and Restore"
You technically have to do both because when you restore the device, it automatically brings along the newest software. (Hence, Updating)
By doing a restore, it also wipes your device clean, everything goes.
That is how you get around 4-Digit PIN