The procedure is identical to that described for the 014 gearbox, see. Chapter 6. The rear end of the output shaft is longer to accommodate the 5th gear. However, when installing the 1/2 gear synchronizer, the outer teeth must be far from the end with the gears (that is, the opposite in relation to the 014 gearbox).
(A link to the original source is available on the website AUDIMANUAL)