solve

 sudoku

As column 6 in box 2 must have a 3, it follows that column 6 in box 5 below cannot have a 3

So c6r5 must be 4 and the last cell is 3
It follows that as the 4 has gone in box 5, cell c7r5 must be 5.
Finally, there is only one place for 4

Continue finding all values for empty cells in the last column of boxes 3, 6 & 9