Before upgrading to DSM7 I uninstalled Plex, then upraded to DSM7. Then i downloaded the latest PMS (PlexMediaServer-1.32.6.7371-b6a09ad81-x86_64_DSM7.spk) for DSM7 and tried to follow the instructions in Synology FAQ - Questions, Answers, and a few How-To's - #34 by ChuckPa. I did not get the expected failure during install and the install did not create a new user called PlexMediaServer, so I could not customize the permissions on it.
I can access the admin page of the PMS, but it has not found the movies.
I now have an old share called Plex and a new called PlexMediaServer.
I only have one volume where everything is installed.
UPDATE: I found the user PlexMediaServer. There was a dropdown with different types of users I did not see the first time. If I changed it to System internal user I found it. So I changed the permissions according to the instructions and uninstalled/installed PMS agian, but it still did not work.
UPDATE2: I needed to needed to use the erase option when uninstalling the new version of PMS after setting the permissions, according to the instructions here Upgraded 1515+ to DSM7 and Plex not working. NOW IT WORKS
