The Eight Puzzle

[A popular puzzle, described by Sam Rebelsky.]

The eight puzzle is a puzzle played on a 3 by 3 grid. The numbers from one to eight are placed on the grid with one empty space. The goal of the puzzle is to place them in order, as in

+---+---+---+
| 1 | 2 | 3 |
+---+---+---+
| 4 | 5 | 6 |
+---+---+---+
| 7 | 8 |   |
+---+---+---+

Give the instructions for solving the eight puzzle with each of the following initial configurations.

+---+---+---+
| 2 | 6 | 4 |
+---+---+---+
| 7 |   | 3 |
+---+---+---+
| 5 | 8 | 1 |
+---+---+---+

+---+---+---+
| 5 | 4 | 2 |
+---+---+---+
| 8 |   | 3 |
+---+---+---+
| 1 | 7 | 6 |
+---+---+---+