Step4. 3 Edge pairs at top layer.

You don't need align the middle layers. Moves, I use, are very simple. If you have good pair of edges, you can solve as 3x3x3.

ex. a: lD'l',   b: (lr')D2(l'r), r'D2rDr'D'r

*******IMPORTANT*******
When you position upper edges in this step, inner cubes at the middle layer must be rearranged. If you pay attention to this inner cube movement,  you can position not only the upper edges, also make pair of inner cubes at middle layers. Normally, the pair will be in row (u or d). In some case, you may pick good inner cube from D layer, then the pair will be in column (r or l). Ofcourse, thinking spends time. In first, you don't need to pay attention about middle inners in this step, too much. After you learned the next step, you had better to do.

ex. 1->2: D2lDl',                          1->2'->3: ulD'l'