Could you please post the question under Data Security Group as this is dedictaed for BDM products?
You can upgrade to S@S 5.0 if you are having either of the below version :
If you don't have either of the above version , you need to upgrade first to 4.1/4.5 and upgrade to 5.0 .
You can get the detailed upgrade steps from the S@S Installation and Configuration guide :
Refer Chapter 4 : Secure@Source Upgrade for the Upgrade steps.