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/olat6.0.1 and install the 6.0.3 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 olat (if olat is a symlink, otherwise: mv olat3 olat6.0.1)
#unzip OLAT-6.0.3.zip
#ln -s OLAT-6.0.3-PUBLIC-XXXXX olat
#cd olat
#cp build.properties.default build.properties
#vi build.properties
#ant install

Update your database manually according to PATH_TO_YOUR_OLAT/olat3/database/alter_6_0_0_to_6_0_3.sql

Now start tomcat.