How to install mod_speling?

Hi,

Newbie here and I'm using TurnKey's Lighttpd - which is awesome!
But, I have a issue when it comes to my game server using it as a fast download server, it won't let the players download the files due to some lines using upper- or lowercase - way Too much work for me to rename all files as a workaround.

I've been searching through the forum and google how to install mod_speling, but no luck :/
Anyone up to describe how to install it from start to end?

Thanks in advance!