I need a replacement oven, not a whole new kitchen - how easy is it to do?

if it is intergrated then it only has four screws holding it to the cupoard (screws are located on the face of the cupboard once you open the door) and will slide out simple enough.

If the kitchen you have is reasonably mordern, so it is a standard size, then it should be very easy to do. Of course, it may be the electrical or gas supply is faulty but even so it should be very easy to do. Regards, Paul Albright