Cell value appears in more than one column, then how to delete the row of the 1st cell value - Excel 2003

[Andrew van den Berg]

The following situation in a file with tens of thousand of rows:
Column M Column N
47-4068 1
47-4677 1
47-4084 1
47-4084 2
47-4085 1
47-4085 2

What to do if i want to delete the bold rows (duplicate values in column M and cell value in column N is 1)???
Do i need a Macro for this? pls explain how i need to proceed then (i am a basic user).
Thanks!!!!

 

[Andrew van den Berg]

No one to help on this? Should not be the most difficult i would think?