Changing Your Window Manager in X

1. Edit the file ~/.xinitrc
2. Add all commands you would like to run when you start up X to this file
3. Add the command to run your window manager at the end of this file
4. Save and exit
5. Restart X

I'm a fluxbox user myself. My ~/.xinitrc file looks like this:

#.xinitrc file

#run imwheel to give my wheel mouse extra functionality
imwheel -k -b 0067

#remap mouse buttons the way I like em
xmodmap -e 'pointer = 2 1 3 4 5 6 7'

#start an xterm on startup. Note this needs to be run in the background
#since unlike the commands above, you dont get the command line back
#when starting an xterm
xterm -bg black -fg gray&

#lastly, start the window manager
fluxbox