The setup requires root access privileges. You need to open the command line and enter the listed commands. After each command press ENTER.
Ensure that the system (and after installation apache too) is using a UTF8 capable locale. The current system locale is set either with the tool "update-locale" or directly in the file /etc/default/locale.
The available locales can be listed with "locale -a". For apache this may be configured separately in the apache config files. For Ubuntu in /etc/apache2/envvars.
For details see: https://www.thomas-krenn.com/de/wiki/Locales_unter_Ubuntu_konfigurieren.
sudo apt-get install apache2