Thanks Marty, yep they are security screws and I tried with pliers as I don't have an allan key or what you need to unscrew them. This is probably really basic noob stuff, but what do you need to take out a security screw? 
they are called torx bits, and you can buy a set from bunnings for about $20 they are handy to own, they are not allan key bits, its really your best option to buy the set so you dont destroy the screw, making it harder to remove,
and edit: do make sure you buy a set with the hole in the center, there are none security versions with out the hole to get over the pin in the center of the screw, that pin is designed to destroy drill bits if you try and drill it out, and make it harder to make a tool your self. most torx bits sets do have the hole in the center but just make sure before you buy.
i was pissed off the other day because i went to change my head box lock from my old head box to the new one, and i had torx screws, i do have a bloody good torx bit set my brother keeps stealing off me and i didnt have on me, its one of those tools if people know you own hide it as you will always be lending it out, the owner ship of this set of torx bits has been a very heated one between me and my brother for a few years now lol, he claims he bought them and i claim i bought them, he has broken into my house to steal them and i have done the same, lol ahaha
