First of all; take a backup copy of your current installation!
Both the directory in the Tomcat webapp and the database!
Again, make sure that you have a backup of your Tomcat webapp!
Unzip the vp_installed_v3.2_upgrade_from_v3.1.1_20080115.zip anywhere on your disk
Start to update your VisionProject database by running the SQL script 'upgrade_from_3.1_to_3_2.sql' located in the directory: 'WEB-INF\internal_docs\installed version\db_scripts\v3.2\Upgrade from 3.1\MS SQL Server'.
Remove all files in the 'web-inf/lib' directory
Extract the content from "vp_installed_v3.2_upgrade_from_v3.1.1_20080115.zip" over your current installation.