First of all; take a backup copy of your current installation, including the database!
Shut down your Tomcat server
Again, make sure that you have made a backup of your Tomcat webapp (all files) and the database!
Extract the content from 'vp_installed_v6.1_upgrade_from_v6.0-20100419.zip' over your current installation.
Go to the directory 'WEB-INF/lib' and remove the file: 'dwr-2.0.5.jar'
Update your VisionFlow database by running the SQL script 'upgrade_from_v6.0_to_v6.1.sql' located in the directory: '/WEB-INF/internal_docs/installed version/db_scripts/v6.1/Upgrade from v6.0'. Choose the directory that match your database, MS SQL Server or MySQL.
You are done and can start Tomcat again!
NOTE! If you like to use French language you have to add ';fr_FR' to the availableLocales attribute in the file: 'VisionFlow.properties', like this:
You can also set French to be the default language on the login page with this:
Then you have to open up VisionFlow and set the Default locale in 'Settings -> General' to French.