Hi Darrell
the SAP delivered rule set should be treated as a baseline or recommendation. It will not contain all the transaction. You will also need to consider any custom transactions that may need to be added to your rule set
Sameel has provided some steps. Regardless of using NWBC Workcenter for Ruleset to create each rule or IMG download/upload functionality, a common step people miss is to generate the rule set so it becomes active.
As an aside, if you have WF activating for Functions and Risks, it is bypassed if you use load functionality in the MSMP.
you will need to discuss with your auditors which other actions (transaction) should not go with to form your SoD rule.