Right, what a f##king day. My missus is well pee'd off as I've been working on the golf all day and I'm going to a show in it tomorrow.
Anyway, its fixed. I pulled the telescopic part of the column in two, dropped the lower bit down the plastic column holder, then shoved a bar down it and used that to hammer the column into the universal joint. Went it very nicely. Then you can reattach the upper part of the column by sliding it down the holder to meet the lower part. I also removed the drivers seat to give me more room to work in.
The only risk doing it this way is that if the lower part of the column wasn't sitting in the UJ correctly, it would have been difficult to get it out to have another go.
The only problem after that was I had damaged the thread on top of the column that the steering wheel nut attaches to. I had to hacksaw off a few mil of the column before the nut would screw on - took bloody ages and was a real brown trouser moment.