grips are for your bars........get down to your local bikeshop/halfords and get the spanner!!
headset and b/b often share the same spanner,2 sizes sharing 1 open end.grips and adjustables are a bodge.......borrow if you need 2!!
also a hammer is fine but a piece of wood is a better bet than a screw driver,you can knock out cups and back in a bit safer,PROMISE!!