how can i replace a clutch on a 1998 1.8 for escort van?

If you have never done anything like this before the best way is to get a Haynes Workshop manual from Halfords, this will deal with yor question in full. Be carefull when you do it as the driveshaft splines can be a pain to re install.

(Peter) mrfixitwilyeo@ntlworld.com
January 2005