RAID 5 Rebuild

I have a RAID 5 server with a failed hard disk. I’m not much into these kind of things but at present I have to perform the replacement / rebuild and I’m not so sure how. Can someone tell me the procedure. Can I shut down the server and insert the new disk? Can i just open the web bios and rebuild manually? Any other precautions to be taken? There are no problems with keeping the server offline for some time.