This assumes you have identified the drive (please see technical bulletin on identifying the drives in the storage array).
Remove failed drive:
mdadm –manage /dev/md0 –fail /dev/sdb1 ( Change md0 to your actual raid device – and change sdb1 to the actual drive in your system you are removing )
Then remove the drive from storage array
Add the drive to the array and run
Add new drive:
mdadm /dev/md0 –add /dev/sdc1 ( Change md0 to your actual raid device – and change sdc1 to the actual drive you are adding to your system )
This should be all you need to allow you to replace the drive and rebuild the array.