How to programmatically change Record Declaration Availability setting?

I am trying to change some of the SPSite (2010) level record declaration settings using my C#custom solution. My code must carry out the following when a feature is activated

1. Activate a bunch of Site Collection (SC) features and Root Web site features. One of the SC features is "In Place Records Management".
2. Change Record Declaration Settings to allow manual record declaration in lists and libraries available in all locations by default.

I am unable to carry out step 2 programmatically. I checked the SC Root Web property bag and find that the only property key related to ECM is ecm_siterecordrestrictions. Please help!

Thanks!