Co-signer on student loan- Please help

Hello,

A couple years ago my grandfather co-signed a student loan for me. I am now graduated and have started making payments about 7 months ago. I recently was late making 2 payments and corrected the situation as soon as I realized I was late. Sadly my grandfather is the one who suffers from my mistake, he "had" almost perfect credit and because of this it has been lowed 80 points. Because of his amazing credit history would he be able to write a letter to have at least part of this reversed?
I feel so horrible and want to do anything I can to help. Your thoughts would be greatly appreciated.