lim is quite intuitive and easy to use. First, you will need to be root to do anything usefuly with lim. Then start X Windows using startx (if you haven't already) and type lim in an xterm. You can mess around all you want, and unless you click on Engage or select Verify & Correct from the Verify menu, nothing will be installed, uninstalled or otherwise changed. If you want, turn on the balloon help from the Help menu and you will get a little floating window of help as you move the pointer around the screen.