resetting up iphone publishing

Pas976

so my old hard drive died and I am moving to a new computer. My games were backed up but not the certificates I have downloaded the wwdr intermediate cert., both dev and distribution certs., and a distribution profile for my new app. when i publish I have a gotten a wide range of error messages saying im missing certificates and now says i have now plst file. what step by step should i download if i have already created all the certificates on another comp.