octavia 2010 door lock barrel removal problem

hi there I'm rab and in need of some help if possible.??

I'm needing to change the door lock barrel on my 2010 Octavia estate as its just spinning when you try opening the door with the key but I'm having difficulty removing the barrel

ive loosened the torx screw on the inside of the door that holds the barrel in place and the barrel is still solid is there something else that I need to do in order to remove the barrel. ??

many thanks rab