How to Add New Metadata From Template

I have 2 new fields coming from my Project Plan -> Metadata -> Roll-Up, and I need too apply it to all existing projects. I see where I can add/modify existing columns, but I need to add new rows to all of my metadata files with cell links back to my project plan. I already went through my blueprint to include these new fields for future plans, but I have about 50 existing plans I need the same update made. Anyone have any ideas on if this is possible and how?

Best Answer