Does anyone know what is involed in swapping the 6-speed from a GLi/R32/20th aniv. 6-speed into a A4 1.8T 5-speed VW ?

My friend and all his other GTi 1.8t freinds bitch about synos and the sloppy shifting of the 5-speed, and he said someone told him he'd have to change A LOT of stuff in his GTi 5-speed to swap in the 6-speed, which sounds like that person just didn't wanna be the one doing it. The GLi and 20th aniv. GTi have the exsact same engine, so why would it be sooo hard to swap a 6-speed in ?

The car in question has less than 15K miles of being extremly babied, and a little bit of racing ( nothing crazy ) and needs new synos. He claims it has always grinded 2nd gear since the day he pulled it off the truck when he worked a VW.

I'm thinking he should be able to get away with getting his tranny warrentied and just pay the difference in the price of the 6-speed over the 5-speed.