SME sys-admin guide walks can answer you in step-by-step procedure, just look under retention.
Now, to point out coupld of things, like *must-know*:
- When you are backing up databases / applications, and if you use SME or for any case other backup products,like SnapManager products, then never configure System Manager OR ONTAP schduler to take/retain/delete backups or create/retain/delete manual backups. If you do, then, it will create holes in the backup products, like in this case is SME!
- If you want to configure "auto-deletion" based on a criteria like, storage capacity, retention based on number of days / quatiity based snapshots, then, you can schedule all this within SME
- In addition, you can setup thresholds for alarming, etc.. within the product as well!
Cheers, balbeer