Ok to update I started to mod this on, the mod is not for faint hearted & does require alot of patients & common sense.
The solution I used was heat to twist the plastic rod that was semi flexible already that stuck up & connected with the gearknob.
The problem is on non S3 stronic cars the button was at the side & the hole that the gearknob metal bar went into to pull the plastic rod upwards was also at the side, where as the S3 stronic has the hole through the rod from front to back, so we had to work out how to twist this rod round to be able to be used with the front facing button & metal bar.
So I pulled the plastic rod upwards, put something into the gear unit below to hold the plastic rod in place all the way up & then stuck a pair of plyers at the top ready to twist it round, got my soldering iron with a different tip that basically is a heating element & slowly heated the plastic rod & began to twist it round, now you have to do this very very carefully as to not burn the plastic to thin, cause it wont fuse thick enough again & just snap of.
So I slowly twisted round & then when in position, removed the heat, remembering to make sure it was completely straight so when the rod is dropped down again it doesnt get stuck & drops down into the gear unit properly, I also used my fingers to mould the still hot plastic round to form a nice thick twist as such.
Now me being uber anal about things breaking etc & its £250 for the part alone, I decided to strengthen the rod more with some epoxy round it & then when solid/dry would dremel it down enough to allow it to go up/down ok inside the gear unit & the new gearknob.
This is where I am currently awaiting the epoxy to harden then will finish of tomorrow, I'll update when gearknob is fully on etc, but here's some images as is, shows after the twist done, then epoxied & then the new gearknob taken apart & you can see the bar that slips into the rod & hole to lift the rod up when button is depressed.