Systematic Approach to follow with respect to the Servicing of the Projector

What are the steps to follow when one wish to blow his or her projector? I bought this slightly used projector last year and it seems it has never been serviced for a long time. There is so much dust in it that it has affected a change in the projecting display of this machine. I wish to service it myself. I wish someone will help me technically in doing this. Thank you.
