1. If there are handful of rules/code changes that need to be roll backed can be done using PRPC delete rule option. This may take few mins but its easier and safer. OR
2. Point your access group, requestor specific ruleset references to correct rulesets. OR
3. Delete rules and rulesets from database using SQLs. It involves good amount of risk element in doing this so.
1. Another approach is, roll back your database with help of DBA to restore to a state tbat was there before release started. However, this approach makes sense only if release is fairly large one.