Somehow I get the feeling that he is speaking about his hdd space...
But if u are talking about ram then those programs posted above should help a little. And if it's hdd space then just delete some files that u don't need.
And u can probably figure out a way to open it without a screw driver.
Or then just go to a shop and buy a screw driver, they are not expensive and u will most likely need them many times in the future.