Not really a diy project. The drum has to be released at one end to slide the belt onto the drum and the belt is murder tight elastic belt that has to be stretched to fit onto motor pulley. If you fancy having a go remove all screws from back panel of machine and lid move drum back far enough to slide belt over front of drum and position belt in right place on drum refit all back panel screws then stretch belt to fit onto motor pulley(access through panel bottom right) Will be praying for you!
Kemjo
March 2012