Change what user Plex runs as

I am slowly working on getting my home lab over to using LDAP (Zentyal server specifically). My media is hosted on a FreeNAS system and I want to have Plex run as a specific user on my Ubuntu server. This user will be a LDAP user. I know there are a few ways to accomplish this. 

1) Change the UID on my Plex server to match the LDAP UID

2) Map the UIDs on my Plex server (LDAP UID == Plex UID)

3) Change which user Plex runs as

Which is the best way to do it?  I think #3 would be best but I am not sure how to accomplish it.