I have a Mercedes-Benz C-Class Sport Coupé C 220 CDi (manual gearbox), June 2003, 10.000km. Recently I found that 1st gear "jumps out" leaving the in neutral. Probably is a matter of tuning the command cables, because it seems that the course is not enough to fix the 1st gear properly. Would you be so kind to tell me how can I adjust cables course?

Many thanks!!!