how can I fix electric windows on audi a4 diesel 1998?

I have just had a problem with my 2000 A6 front windows -- the cables that run through the electric motor have snapped 1 from rust (happened 2 months ago) and other from frayed wire .. need to replace the whole cable system .. not sure if the whole kit has to be replaced or just the cable .. I'll be making inquiries this week (31 March 08)

Andy
March 2008