Take a backup of the GoCD DB (and everything else) before attempting this. See the documentation to find out where the DB files are.
NOTE: Make sure the GoCD server is brought down (so that it does not have a lock on the DB) before attempting this.
Risk level: Low, since this works on a copy and you can always put everything back exactly how you found them before. But, that implies that you've kept track of what you've done, carefully.
$ ls
artifacts/ bin/ config/ cruise.war db/ felix-cache/ lib/ LICENSE logs/ plugins/ plugins_work/ run/ work/ wrapper/ wrapper-config/