Schematic boxes

Is there a way to edit what’s in the dwg boxes?

If you mean the drawing sheet with fields at the bottom right corner some fields are filled in from File > Page Settings.

Thanks I’ll try tha.
How can I make my small schematic larger inside the letter size frame?

Choose a smaller paper size. I often use A5 instead of A4. When and if it’s printed it will get magnified on paper.