Newbie - Pre-boil

Hello All,
I'm new to BS2 and back to brewing after a 15 year hiatus.  Please direct me to a thread if it already exists, but here's my question.  I have grains that steep for 30mins before the boil.  How do I add them to BS so they are in my timer/OG/etc?

If your recipe is set to "extract," then this is already in the timer instructions.