How to change Window Managers "on the fly"

Want to try a new window manager?
It's easy! Just open a terminal and run one of the following commands:
xfwm --replace &
metacity --replace &
icewm --replace &
compiz --replace &
unity --replace &
Then just reboot to see the results.

How to find the current Window Manager in Linux

To find current Window Manager open a terminal and run:

wmctrl -m

This will return output similar to the following:

Name: Metacity
Class: N/A
PID: N/A
Window manager's "showing the desktop" mode: N/A

Metacity is the the Window Manager in the above example.

How to remove old programs

To remove old programs run: popularity-contest > out.txt
Note: You may need to install popularity-contest first. Do this by running:
sudo apt-get install popularity-contest 

The newly out.txt will contain rows simliar to following:

POPULARITY-CONTEST-0 TIME:1359204011 ID:ae1dc87f150c489082f0ddb28af40350 ARCH:i386 POPCONVER:1.53ubuntu1
1359204011 1349657211 openbox /usr/bin/openbox
1359204011 1349657211 xscreensaver /usr/bin/xscreensaver
1359204011 1354294761 perl-base /usr/bin/perl
1359204011 1349833421 update-notifier /usr/bin/update-notifier
1359204011 1349657224 xfconf /usr/lib/i386-linux-gnu/xfce4/xfconf/xfconfd
1359204011 1349657224 lxpanel /usr/lib/i386-linux-gnu/lxpanel/plugins/monitors.so
1359204011 1349657225 policykit-1-gnome /usr/lib/policykit-1-gnome/polkit-gnome-authentication-agent-1
1359204011 1358559008 lxterminal /usr/bin/lxterminal
1359204011 1349664550 ttf-ubuntu-font-family /usr/share/fonts/truetype/ubuntu-font-family/Ubuntu-RI.ttf
1359204011 1349664535 pcmanfm /usr/bin/pcmanfm

Note: Programs manually compiled and installed, unzipped or unrarred are not in the above list. 

The first two rows are time and then date in Epoch format. These will need to be converted to regular date/time. 
Open out.txt in a spreadsheet such as Libre OfficeCalc. 
Add a column after the time and after the date. Fill the empty columns with formulas to convert them. 
For the first time use: For the first row of data, assuming the first "epoch time" cell is in A2, put =(A2/86400)+25569 in B2. 
Do the same for the second "epoch time", using =(C2/86400)+25569 in cell D2. 
Then sort the sheet as applicable. 
You then remove the programs using the syntax: 
sudo apt-get remove <program name> 
where <program name> is the program you want uninstalled.