The immobiliser is integral to the whole system.
If you try disconnecting it the car simply won't work.
If it was as easy as disconnecting something then it woildn't be much of an anti theft device.
You could try temporarily removing the ID4 immobiliser chip (should be a little glass tube) and taping it to the part of the key that the fob clips into.
Be warned that it's very fragile.
Very very fragile and if you break it its buggered
Why send the key away anyway, there are plenty of replacement fobs on ebay, probably for a lot less than what you'll pay to have the new switches fitted to yours.
Get one of those and simply swap your transponder chip and key blade onto it, sync it to the car and away you go