Removing the MeMenu
To only display the session manager, launch gconf-editor from the terminal or the "Run Application" dialog (call by pressing Alt+F2). Next browse to /system/indicator/me/ and change the vaulue for display from 1 to 0.
Or you can just run this command in the terminal:
gconftool -s /system/indicator/me/display --type int 0
To re-enable the MeMeun, run:
gconftool -s /system/indicator/me/display --type int 1
Try:
sudo apt-get remove indicator-me
If you also want to get rid of the Messaging Applet:
sudo apt-get remove indicator-me indicator-messages