Seat Belt Removal???

After removing my standard cloth interior yesterday and replacing it with a VRS leather interior, I realised I had forgotten to remove the seatbelt 'buckle' off the cloth seats to place on the side of the VRS ones..

After removing my VRS seats again today, It looks like I need a torx screw of some sort to remove the bracket holding the 'buckle' bit onto the side of the seat.

Can anyone shed any light what size torx key I need??

I really need a quick answer, as I need to put seatbelts into the car!!!

Thanks!