P25: This process is quite simple, create your new P25 Reflector using the software available at this Git Repo. Once you have your reflector running, submit a change against this file to have your new host included in the Pi-Star P25 Host list.
NXDN: This process is quite simple, create your new NXDN Reflector using the software available at this Git Repo. Once you have your reflector running, submit a change against this file to have your new host included in the Pi-Star NXDN Host list.
Note: Please stick to the standard port nubers of 41000 for P25 and 41400 for NXDN unless you really have to change it, the Pi-Star software includes a firewall that restricts outbound conections to the required ports.