IPhone : APNs iOS certificate

A bunch of my clients APNs certificates are expiring for his iOS apps, and he wants me to renew them. I created new ones and downloaded them, then double clicked them and keychain opened. I am wondering if this is all I needed to do (does it associate the new certificates with the developer account?)? Or is there more? I just took on this work, and am enjoying it... but want to make sure I am doing it right. Learning process. I have read that you need to export the certificates to the server, how would I find out what server and where on the server to put it if I need to? The only third party Push Notification service he uses besides hard coded Push Notifications is AWS, and as far as I'm concerned that is not an issue right now. Just the certificates on the developer portal. Thanks a lot for any input! Sucks working with someone else's coded apps