Increasing capacity 5D3

I have a 5D3 with four 4TB enterprise drives. I need to increase my storage capacity. I want to replace the four original drives with four new Seagate Enterprise Capacity 3.5 HDD 10TB drives without losing data.

I am hoping to be able to add a 5th drive, then wait for a while to let the data be distributed in the array then start swapping out the old 4TB drives one at a time.

Back in the day when I was running a simple Raid 10 array, I could just start swapping drives with no problems. My old drives were still readable and I stored them in a safe. From what I have read Drobo does not use the same kind of duplicate sets of data so the drives are only usable if they are all loaded.

What is my best option? I really like the speed of the 5D3 on my iMac Pro, but I had not anticipated the problems that I now face trying to increase capacity and archive my older files. I appreciate any pointers you may have.

No quick and easy way, other than a drive at a time. Drobo uses a RAID 5 or 6 depending on how you have it configured.