How to replace the value in excel

Hi ,

I have duplicate values available in the Excel & i want to replace with Random Value

For Eg:

I/P

Farha232
Farha232
Farha232
Farha231
Farha232
Farha234

O/

INV234
INV234
INV234
Farha231
INV234
Farha234

Please Help

You want to replace the duplicate values of all column in a excel or in single column only?

single Column