you could try Autoscout.ch, when you have a buyer, you go either together to the verkheersamt and hand over the grey card. The buyer has to have a valid insurance certificate, and the transfer then takes place, you then have to hand in your number plate. This is kept for a year in case you buy another car. Or the buyer gives you the cash value of the car, and takes the grey card himself to the Verkheersamt, you keep the car and the keys of course, until they return with the card in thier own name. Its quite a simple operation. Just remember not to give the plates to anyone else . 

you also have to make sure your car is still "expertisée". otherwise, the buyer will have to do it at their cost or they won't be able to get the grey card approved.

that is why, selling in exchange for a new car from a garage,  may be a better solution!

hi, many thanks for ur time, best regards

Thanks for all the advice. Very useful - esp. given complete lack of knowledge myself.

hi if u havetime internet is the best way, if not garage is the only option I think...

You can also sell it through annibis.ch

I think its called anibis.ch with one n, not as a critic to you ok.  But I guess autoscout will do it as well.

Expertise with the TCS, then buy on ricardo. The cheapest and most efficient way to buy you car at a good price :-)