If you have the files downloaded, which i assume you do, do the following:
Open a terminal window (right click on desktop and click open terminal)
Type in su and enter the root password when prompted (if you have never provided a root password to the system, just ignore this line as long as you're using the first account made on the system)
Go to the directory that holds the .rpm files by using the cd command.
(cd [path to files, such as /home/supermaton/rpms/xine]) If anything has a space in it with the cd command, such as my rpms as a folder, enclose it in quotes (/home/supermaton/"my rpms"/xine)
Type ls (this will show the files within the folder.)
Type alien name of rpm
for each rpm. This will create a file with the same name followed by the .deb extension.
Type mkdir /home/binary (this will create a folder called binary in the home folder)
Type mkdir /home/binary/binary
For each .deb file made, type mv name of file
/home/binary (this moves the files)
Type cd /home/binary
Type dpkg-scanpackages . /dev/null | gzip -c -9 > Packages.gz (feel free to copy and paste this line...I did the first time I saw it
. That | is the shift of the \ key)
Type cp Packages.gz /home/binary/binary
The purpose of all of this was to convert the .rpm files (for redhat and fedora core) to .deb files (for ubuntu and other debian-based distrobutions). Now you need to install them.
From the desktop, go to system-administration-synaptic package manager and type in youre password when prompted. Within synaptic, go to settings-repositories. Click add, then click custom. When it asks for the APT line, type file:///home/binary binary/
Click Add repository, then click OK. Click the boxes next to the following files: w32codec, libxine1, and xine-ui. Once the three are checked, click apply. The packages are installed.
To use xine, enter into a terminal and type xine. Right click within xine, and there are a ton of options. If eveything went well, you can now play mp3s.