Quartus 10.1sp1 on Ubuntu 10.04 install problem

I follow "installing altera quartus 10 web edition on ubuntu 10.04"(sorry, cannot paste link) and try to install Quartus 10.1sp1 on Ubuntu 10.04.

The critical step is to remove libX11.so.6, but I cannot findlibX11.so.6 under bin directory. And if I keep everything, the GUI will not show up. Any suggestion? Thanks!