Switch on EL wire with Raspberry Pi

I have bought a small 3 m length of EL wire along with a portable 3v controller like this one:

http://www.elwirecraft.co.uk/340/portable-inverters/portable-driverinverter-for-3-metres-of-el-wire-2xaa-batteries/

there is a tactile push button which cycles through the operating modes (on, flash, off etc)

id like to be able to turn the EL wire on using my raspberry pi.  I have opened the controller and soldered 2 wires over the push button contacts such that when you touch these wires together, it has the same effect as pushing the button.

thats as far as I have got.  Has anyone got any idea on how to us the raspberry pi GPIO to switch this on?  Transistors are a bit foreign to me, especially ratings and required resistors!

Either use transistors or use a relay. Plenty of information out there about using transistors as a switch.