You should have a whole bunch of .debs in the DEBS folder. Ok it's quite easy:
1. Open a terminal and navigate to the DEBS folder.
2. type this is the terminal
3. You will be prompted for a password; supply your own, not the root password.
4. Your Openoffice installation should be found in /opt/openoffice.org3.
You're all set and ready to go.
There are installation instructions on the openoffice site. You might want to have a look at them if you encouter any problems.