Install OLAT as described in the installation chapter but DON'T RUN 'ant dbsetup'!! We recommend to move your existing installation from PATH_TO_YOUR_OLAT/olat3 to PATH_TO_YOUR_OLAT/olat3.2.1 and install the 4.0.0 package as your new PATH_TO_YOUR_OLAT/olat3. All user data is located in the olatdata directory which should not be located in the PATH_TO_YOUR_OLAT/olat3. The olatdata directory and the database won't be changed when installing the new code.

#cd PATH_TO_YOUR_OLAT
#rm olat3 (if olat3 is a symlink, otherwise: mv olat3 olat3.2.1)
#unzip OLAT-4.0.0.zip
#ln -s OLAT-4.0.0-FINAL-XXXXX olat3
#cd olat3
#cp build.properties.default build.properties
#vi build.properties
#ant config-all
#ant install

Update your database manually according to PATH_TO_YOUR_OLAT/olat3/database/alter_3_2_1_to_4_0_0.sql

Now start tomcat. The first launch might take some time if you have a big userbase and a lot of groups because the efficiency statements for each user get calculated. The efficiency statement calulation runs only once.