Download package xulrunner-x.x-source.tar.bz2 (x.x is to be replaced with the actual version number). It is available from http://developer.mozilla.org/en/docs/XULRunner too.
Move it to the home directory
In the terminal, to verify the package is there, type
ls
To unpack xulrunner type
tar jxf xulrunner-x.x.tar.bz2
To enter the newly created directory, type
cd mozilla
To download a configuration file, type
wget http://www.nongnu.org/bibledit/dot.mozconfig
To give this file a proper name, type
mv dot.mozconfig .mozconfig
To configure xulrunner, type
./configure
Watch many messages, but no errors.
To compile xulrunner, type
make
Watch many messages, but no errors.
To install it, type
sudo make install
Watch many messages, but no errors.
As root, copy all the files and directories from /usr/lib/xulrunner-x.x.x.x to /usr/lib. To do this, type
cp -r /usr/lib/xulrunner-x.x.x.x/* /usr/lib
In the above command the "x.x.x.x" should be replaced with the actual version number, for example "1.8.0.4". If it asks to overwrite any file, answer yes.
To go back to the home directory, type
cd