Uninstalling / upgrading PostgreSQL on OSX
try to use the edb installer to upgrade your postgresql version[1].

If you want to make your life easer, I recommend you backup your databases, uninstall your current postgresql configuration and use the postgres app[2].

For a full list of installers, take a look here[3]

Hope it helps.

References:


http://www.enterprisedb.com/products-services-training/pgdownload#macosx
http://postgresapp.com
https://www.postgresql.org/download/macosx/