Engine will not idle when cold??

[lessteaks]

Hi there. I've a 1995 E220 CE.

Starting my car from cold in the mornings it just dies if you take your foot off the gas but once its hot it runs perfectly well (even after driving 100m or so)

A friend suggested that it may be temperature sensor? If so, how easy it it to change (no experience, appreciate detailed as possible description!!!) or would I need a mechanic?

Thanks a million,

Cheers,

Les