Very Easily, Remove top of dryer and also remove vent pipe from bottom so you have access to the motor pully. Take off screws holding rear of dryer to sides so that the drum can be pulled away from the felt at the door and the replacement belt slipped over. then slide belt onto the track were the old belt used to be and sellotape it to the drum at 3 locations. Then replace screws to the back of the dryer and then set dryer face down on the floor with the top against a wall. You then take the broken belt and thread it through the slot in the floor underneath the motor pully, around the replacement belt and out the other slot in the floor. You will then need an assistant to pull the belt very hard to stretch it while you guide it over the motor pully with your hand through the vent pipe opening. You should then remove the broke belt and turn the dryer upright and spin then drum to ensure the belt is seated correctly. You should also then put the dryer back together and run it for 15 minutes of so while supervised to ensure you havn't moved or broken anything which may cause a fire.
Mark from Ireland, October 2008