code for comparing two .xls files(excel documents) in c sharp .net

Question

Hi all,

I have two excel files.
In each file  two columns are there.
In first file ID And FirstName columns are there.
In second file ID And LastName columns are there.
In both files ID column values are same.

Now my requirement is compare those id columns in two files and replace the FirstName Column(in First File) values with SecondName Column(in Second File) values to corresponding ID's.

Please post code to this..