Put the three files (lejos_2_1_0.tar.gz, Intellego_2_0_Student.zip, and
Patch.tar) into a directory, then go into that directory from the command line 
and do the following:

Extract & compile Lejos:
# tar -zxf lejos_2_1_0.tar.gz
# cd lejos_2_1_0
# make

Extract Intellego and patch:
# cd ..
# unzip Intellego_2_0_Student.zip
# tar -xf Patch.tar
# cd Intellego_2_0

Setup environment variables:
Edit Intellego.sh and util/setup.sh using text editor for proper paths to the folders.
Example:
   export INTELLEGO_HOME=/home/ian/LegoRobot/Intellego_2_0
   export LEJOS_HOME=/home/ian/LegoRobot/lejos_2_1_0


Start simulator:
Run Intellego.sh by typing either
# ./Intellego.sh
or
# sh Intellego.sh


NOTE: If any of those command fail then you may need to install the needed
executables (such as gcc/make, unzip or tar).