For this document, I assume you have a good undestanding on how to install a package and how to use Flexcel...
The packages to install in Kylix begin with a "K". For DELPHI, you have to install KFlexCelReport, KFlexCelXlsAdapter and KFlexCelDesign.
To be able to generate reports, you also need libgsf (and its dependences, libglib2 and libxml)
I downloaded libgsf (v1.2) at ftp://ftp.gnome.org/pub/GNOME/sources/libgsf/ you can search the web for it, anyway. Of course, get the latest version that works...
If you don't want to use libgsf, there is also a port of libole2, but it doesn't work ok with workbooks with many storages. If you KNOW what you are doing, you can replace KGsfStream for KOle2Stream in the source code.
There is no demo for FlexCelReports, not because it would be difficult, but because there is no standard dbdemos database to link the demo. But it works the same as in windows. The XlsViewer demo DOES run on kylix.