Changing the number to datafiles

Hello All,

We have an ecc system running on ms sql server. The database has 4 data files each of 900 GB and because of this huge data files we are facing problem with the backup and restore.

So for avoiding this and other issues we have planned to change the number of data files from 4 to 12. So can anyone suggest idea and approach for performing such task.

Regards,

Mohit