The most common cause of the alternator light and the brake warning (!) led to light up is worn alternator brushes. If you want to get your car fixed in a hurry, then do the following:-
- Remove the air filter
- Undo the alternator brush holder's connections
- Very gently file down the lip from the alternator's brushes with a miniature rat's tail file
- Refit the brushes and air filter.
Alternatively, you could order a new set of brushes from the VW Classic Parts Center
http://www.vw-classicparts.de/ , VW part number 0409035031 at €29.86 (excluding 19% MwSt - german VAT and postage) and will take a while to arrive (I think the blue square means that they will have to be ordered in from elsewhere).