Hi,
Delete all the files that you have in the directory where
you have feedback server installed and then copy back the content of the new
installation zip to that directory. Once this is done use the http://yoursite.com/fs_install web
database installer, enter your DB information and upgrade your db to the latest
version, no data will be lost during that process. Make sure to back up all the
files / data prior of upgrading to the latest version.
Note that if you used the system message editor to translate language files to keep all non us.xml en-us.xml and native.xml files and then copy them back to the fsxmldata/languages directory.