I have bought a new barrel lock to replace broken one on my 1.6 Astra, but cannot remove the old lock. Have removed top and bottom covers behind steering wheel and dir. ind switch lever and w/wiper switch lever also ignition switch on left side of s/wheel. There is a locking pin on top of ignition barrel which can be accessed via a small hole somewhere above the ign. switch. The problem is I cannot see any way to remove plastic framework on the steering column which is obscuring the hole. There is also a small flat box under steering column which houses central locking electronics. I cannot see any obvious means of removing this either. Hope someone will help me with this.