stuck on levlel 70 !!! can not figure this one out

can anyone help me??
thanks
kathryn

if you move the middle rocks to the far left, about4-5 of them, then take the second rock from the left and push it alongto the right, do the same on the right side, blow up the rock covering the magnet. What you are trying to achieve is a clear path above and below the buttons by stacking the rocks up either side as much as possible. clear the yellow pieces from both lots of buttons but don't remove too many or the rocks will fall down onto the buttons. Then blow up the bottom rows of rocks and clear the final yellow pieces blocking the bottom buttons. Hope this helps, cheers- Valery