I have an old PGP using old GnuPG algorithm defaults. According to Best encryption and signing algorithm for GnuPG: RSA/RSA or DSA/Elgamal?, those algorithm settings are no longer sufficient, so I want to move my PGP key to more secure algorithm settings. What is the best way to do that? Do I have to revoke my key and create an entirely new key?
There is no way to "upgrade" an OpenPGP key. You will have to create a new one, and you will loose your reputation in the web of trust.