First of all; take a backup copy of your current installation!
No database changes has to be done so you only have to backup the Tomcat webapp!
Again, make sure that you have made a backup of your Tomcat webapp!
Unzip the vp_installed_v5.0.1_upgrade_from_v5.0-20090511.zip anywhere on your disk
Remove the file 'itext-2.0.2.jar' from the 'web-inf/lib' directory
Extract the content from 'vp_installed_v5.0.1_upgrade_from_v5.0-20090511.zip" over your current installation.
The file WEB-INF/classes/visionproject.properties have now been replaced and you have to update the properties below to what you had previously:
You are done and can restart Tomcat again!