In this clip I will lay out drilling attached the base sides to the concrete. First I will set the sides in place while someone holds the post. I'll mark the concrete in case the sides are to move. I'll know where to put it back. I'll drill a hole through the 2 x 4's in the concrete either with a hammer drill or compactor. I'll then set screw, the tack on screws into the concrete. Next we will repeat the same on the other end of that side and then we will do the same with the other side.