change value of prefab field in a array of prefabs

Hi i have array of SpikeArea prefabs ![alt text][1] each prefab has a field called Area Size ![alt text][2] I want to know how can i expose Area Size field in the AreasList array above so that i can assign different values for each of the same prefab SpikeArea...(other than making different prefabs with just changing one field) [1]: /storage/temp/164464-gc.jpg [2]: /storage/temp/164465-sa.jpg