Replacing old PGP keys with new PGP keys.

Hello Everyone, 

I am facing problem regarding replacing keys on server, I have to manually delete the old keys and upload new keys, can't it automatically upload new keys replacing the old one, I am using PGP in one of my mobile application, I am using LDAP provided by UnboundID SDK to upload or retrieve keys to-and-from server.

Any help will be very beneficial,

Thank You!.