Security/safety circuits in removable cell phone batteries?
The easy way to do this is to grab one of your existing batteries for the phone.  Take it apart and remove the defective cell.  Then connect your new (larger) cell in place of the old cell.  

You will most likely have to use extension wires to allow the battery case to fit in the phone.  Make sure those wires are decently beefy - 20 AWG or so should be good.