Right-click the skin > "Edit skin". I allow the graphs to be easily resized using the user customizable values near the top, but resizing text and spacing requires delving into the code further down. Adjust the values for [sNum]'s FontSize and [sGraph]'s Y.
This skin has no GUI, you must use the Rainmeter system tray menu to interact with it.
Right-click on the Rainmeter system tray icon > Snow > Unload skin