1995 Volvo 440

Hi, I have a pretty old but sturdy Volvo which has been stalling at the lights recently. Wouldn't start up a couple of months ago and the callout mechanic said it was due to condensation in the distributor cap, which he cleaned out. Everything was fine for a couple of months, but now stalling at idle again. Is the distributor cap easy to replace, as in could a fairly intelligent amateur with the Haynes manual replace it? Or should I just bite the bullet and take it to a garage? Money's pretty tight at the moment. Many thanks for any advice, Bob