Sharepoint change ribbens icons image

In SharePoint 2010 there is an image called formatmap32x32.png which holds all the icon image for the ribbon.

I am building a masterpage and almost done with. The only thing missing is how to change this image programmatically to my own redesigned icons so the user who's going to use my master-page doesn't have to change the image manually by replacing the default picture in the images folder in sharepoint?

the icons should be in one image just like the default one from sharepoint.

the is the default image:

http://s23.postimg.org/j9fqu2iqz/formatmap32x32.png

Any one have any idea on how to?