You can follow these steps to install your PPM license key:
1. Copy the 'license.conf' file given by HP Support to a local directory.
2. When prompted from the installation program, enter the location of this license.conf, and the installation program will copy the file into the conf directory.
3. Proceed with the installation as guided.
Here are the instructions for change a new license key to an existing system:
1. Stop the PPM server.
2. Replace the license.conf file in your PPM_HOME/conf directory with the new one.
3. Restart the instance.
Note: please verify that license key matches with the IP address of the machine.