What Corion is telling you above is to ask your systems admin if the command bunzip2 is already installed. On lots of Linux systems this command is installed as part of the OS. If the sysadmin's answer is "yes", then you can use the technique above that Corion has shown you.

For example, below is my login session to Linux system which I do not control, but it has the bunzip2 command already installed.

[myid@corphost4~](155) $ uname
Linux
[myid@corphost4 ~](156) $ bunzip2 --help
bzip2, a block-sorting file compressor.  Version 1.0.3, 15-Feb-2005.

   usage: bunzip2 [flags and input files in any order]

   -h --help           print this message
   -d --decompress     force decompression
   -z --compress       force compression
   -k --keep           keep (don't delete) input files
   -f --force          overwrite existing output files
   -t --test           test compressed file integrity
   -c --stdout         output to standard out
   -q --quiet          suppress noncritical error messages
   -v --verbose        be verbose (a 2nd -v gives more)
   -L --license        display software version & license
   -V --version        display software version & license
   -s --small          use less memory (at most 2500k)
   -1 .. -9            set block size to 100k .. 900k
   --fast              alias for -1
   --best              alias for -9

[myid@corphost4 ~](157) $ which bunzip2
/usr/bin/bunzip2
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