If you can get your hands on a USB CD drive, that might be worth a try. I used one to install DSL on a notebook a few years newer than yours. Sadly only to give up thanks to lack of drivers afterwards.
Sadly, the Libretto L5 has exceptionally picky USB boot support, only works with a very small selection of drives that were mostly not sold in the USA. So not really an option.I actually have all the drivers for it from an old fanforum for the series ^.^'...





