Here is the video explaining how to use md5sum: http://handsonerp.com/oracle-financials-tutorials/76-03-oracle-e-business-suite-installation-inst/6338-verifying-oracle-stage.html

md5sum check has nothing to do with the installation method. It is simply a check. I did not include this verification check in the old videos. I noticed some people had file corruption issues in the last round, therefore this time I included a step to verify if the stage is good before proceeding further.

Removing Installation:
Make sure all services are stopped. Reboot the machine if you are not sure.
Issue "rm -rf PROD" command from Oracle home. This will forcefully remove the PROD folder.