1) Downloading the distribution
The binary pre-compiled distribution of XFCE is a gziped tar archive. The application is compiled with XForms statically linked, so you do not even have to set up XForms on your system.
2) Installing the distribution
The archive contains the right path, so all you have to do is unpacking
it at the root
Just a few tips on how to use RPM (for more informations about
RPM, please use rpm --help or man rpm) :