How difficult is it to replace a timer on a tumble dryer?

I have been told that our tumble dryer requires a new timer. I have located the correct part from E spares. Is this something I can do myself or do I need a qualified person? The part looks as if it can be "plugged in". We have been given the run around by the local domestic appliance repair company and would really like to do this myself. I am reasonably proficient at DIY!