This is from my emergency response notes. I neglected to mention the Solaris version and no longer have a recent Solaris box to check this on, so check the manpages and give it a try if it seems appropriate.
First things first, you must
umount any volumes on that disk, disable swap on it, and in every other say stop using it (e.g. if you're using Solaris software RAID). If you're using Veritas, check out rkosegi's answer.
Then, find out what
cfgadm calls the disk:
The left column is the disk designation. Yes, I know, yet another format. At least this one includes the short block device name so it's not too difficult to find. Anyway, once you know it, say something like this: (based on your question, but do check first):
cfgadm -c unconfigure c0::dsk/c0t1d0
You can say
cfgadm -al again to make sure the disk has been unconfigured. At this point, if your machine has hot-swappable disks, the disk will have been tri-stated, powered off, and controllers, backplanes etc. will be aware that you're about to remove it. If the disk has a ‘ready to remove’ light, it'll illuminate.
Once you're done replacing it:
cfgadm -c configure c0::dsk/c0t1d0
Once the disk is configured again, you can proceed with the rebuild. Good luck!