Hi Eileen. You dont say which type of dryer you have but 90% of them have a filter tray which is slotted into the bottom half of the gap between the door and the drum. It should just slide out. To be effective your machine should be discharging a positive draught, so make sure any discharge grills and hoses and vents (if fitted) are free of fluff and lint as well.
You should not have to strip the machine down to do any of this as there is a regular need for the user to keep the machine free
Cledlyn
July 2008