How to Index Custom Product Attributes (Technical Specifications)

Hello,

We are planning to upgrade from Apache Solr to EPiServer Search & Navigation. We were able to use the out of box configuration of Episerver search & navigation index all the catalog entry items. we have a custom BFO which stores the attributes (RAM, Processor Type, HDD Size etc.,)  for these products and our existing indexing job used to index these attributes and performs a faceted search on this attributes. Can someone guide me in the right direction to perform the same task (faceted search on attributes) with EpiServer Search & Navigation?

Thanks,

Naveed Quadri