Copying site to subdomain for testing

I have a REVO 2.0 site on mysite.com and I want to copy it to a testing space (a subdomian) test.mysite.com, I have installed modx revo successfully on the subdomain. I now need to copy the exsiting site across, I tried http://rtfm.modx.com/display/revolution20/Moving+Your+Site+to+a+New+Server though I get stuck at 'Packaging up your files' how do I run the 'tar -czf /path/to/backups/modx_revo_site.tar.gz /path/to/modx_doc_root/'

Any help much appreciated!

You would need to run the 'tar' command from an SSH terminal after logging into your webserver, assuming that your on a Linux/Unix OS. You can also use any GUI type zipping tools (7-zip, WinZip, Compress, etc.). Then simple move to the new location and unzip and rerun your setup.