Transpose a matrix without a buffering one

How is it possible to transpose a MxN matrix without using a "buffering" matrix? In the latter case it's easy and quite the "classic" approach...

Given a matrix[M][N], I would like to put it into a void transpose_matrix(int matrix[][]) function which operates directly on the matrix passed as reference which, as previosly said, would edit the matrix memory space to transpose its elements.

e.g:

A =

1 2 3 4
5 6 7 8
9 1 2 3

A after transposing itself (without pretty printing)[1]:

1 5 9 2
6 1 3 7
2 4 8 3

Thanks!

[1]: Printing the matrix as if it was actually a "new" NxM matrix.