[otrs] Another newbie question (blamy!)

Hi there, I've installed OTRS 2.04 with a few modules missing, see list below: Net::LDAP ... not installed! (for directory authentication - not required) GD ... not installed! (for stats - not required) GD::Text ... not installed! (for stats - not required) GD::Graph ... not installed! (for stats - not required) GD::Graph::lines ... not installed! (for stats - not required) GD::Text::Align ... not installed! (for stats - not required) XML::Parser ... not installed! (required for strong xml use - not required!) But now I need to install missing modules. PackageManager won't work, because of the XML::Parser missing, I think. How can I do that? Cheer Dudes! Ciao, Filippo