Replacing SAS drives to SSD drive on Proliant DL360p servers

Hello,
One of my HP DL360P servers will be upgraded with SSD drives. I have two arrays. The first one use raid 1 for the operating system. The second array uses RAID 1+0 on 6 drives. I want to replace the second array with larger and faster SSD drives. My question is very simple. Can i disable the second array and replace the drive with SSD while the machine is running, or do I have to shutdown the machine, replace the drives and then configure them in the Smart Storage Administrator? Sorry if my question seems stupid but since I haven't done this on an HP server with a Smart Array P420i, I prefer to ask first in case I am missing something. Thanks in advance.