Thin insulation type suggestions

I have bought a new Windows smart phone, it is a great phone but I got it on the cheap because it is surpless stock. As a result the sound output connector is not standard, it is 2.5mm but using the normal wiring one is speaker on the headphone is a mic and the other is a phone, so music comes out only as mono.

I have been told you just need to short out the middle contact on the jack which disables the mic and enables stereo mod, but to this I need to put type round the jack.

Any ideas of how to insulate part of the jack?

 

Just used managed to use some selotype and its now stereo

 

Well selotype prooved the theory but it dosn't last, so I need some way of insulting the middle part of the jack which will last.

 

erm.... insulating tape

 

is too thick, it won't push into the socket then.

However there is another issue insulating the middle conector means there will only be two connectors there so how can it possibly be stereo?