There are multiple ways to upgrade your existing version of Access Manager to the new 1.4 version. Depending on the version of Access Manager you are currently using you have specific processes you can use to perform your upgrade or migration, the links please see the links below for the instructions for each process:
If you are already on version 1.4 new versions will appear available in Configuration > Updates and can be applied from there.
Directly upgrading an installation of Access Manager 1.3 to 1.4
Migrating the configuration of Access Manager 1.3 to a fresh 1.4 system
Migrating the configuration of Access Manager 1.2 to a fresh 1.4 system