The tubing doesn't need to be replaced unless there are cracks in them. Sometimes you may need to snip a little bit off the ends if they seem to have been stretched out where they connect to the flange part of the pump. You should replace the membranes (the little white flappy ones) about every three months if you use it daily.
The rest of the parts you should be able to boil in order to sanitize them.
Trish~mama to Kaelie 5/03, Amelia 12/13, and someone new coming 11/15, surro mama to Aidan 2/08 & Ellyss 6/09,