How to update LMS on Ubuntu 14.04?

Hello,

I currently have LMS 7.8.0 installed on ubuntu 14.04 LTS. I downloaded version 7.8.1. I ran the "sudo service logitechmediaserver stop" command. Then I tried to execute "sudo dpkg --install [name of new file.deb]", and I get this error message:

dpkg: error: dpkg status database is locked by another process


What do I need to do? Do I need to completely uninstall 7.8.0 first? I don't want to lose any of my settings. My linux skills are very limited.

Thanks!