KgCO2/m2 to KgCO2/sf

Probably the easiest way is to change the settings from metric to ye olde imperial (and vice versa). Otherwise to convert from kgCO2-e/m2 to kgCO2-e/ft2 you can multiply by 0.092903

This link explains unit conversion with a few examples: How to Safely Convert From One Unit to Another