Ignition Switch Removal.....

Really need some advice before I give up and it goes into the VW stealership...after the advice on how to remove the airbag safely my Dads had a day off and tried to replace the lower half of the ignition switch which is worn and causing me starting problems..you need to lift and wiggle the key to get a good connection...I have been told this is a comman fault so someone else out there must have done or had this part replaced...the main problem is once the steering wheel is off, wiper/indicator stalks etc off silly little shear bolt removed you cannot pull the alluminium housing off because of a splined sleeve on the end of the steering column, theres a spring behind this and the aluminium housing..guess its a safety feature?

So aftervarious attempts with various pullers how do you get the ignition switch housing off to replace the plastic part at the base that the electrical terminal plugs into.. is it a simple job and he`s going around it wrong or is there a special puller only VW own. HELP PLEASE!!!!!!!!