You can do it either way. "remove disk" also deletes teh partition on the disk, so when you connect it back up, it does not appear as if it is a RAID 5 volume "missing three disks", which could be confusing.

I wanted to swap out a drive with my RAID 5 Thunderbay 4 so I can expand the size of my volume.

It seems like there are a few different methods to do this. The instrucitions say one way but I found an YouTube that suggests slightly different.

What I did was in SoftRAID remove disk from the volume then I went to unmount from SoftRAID but that option was not there and only option was to mount (The volume was already Mounted) So I ejected via finder..

Shut down the unit. 

Swapped the Drives.

Turned it back on.

In SoftRAID Initalized then Right clicked on the volume and selected Add Drive.

Is what I did above the best and correct steps?

The manuals that I located all say to skip the remove disk from volume in SoftRAIS and just swap Drives then Add Drive via SoftRAID..

Also when the Volume is rebuilding can I close out of the SoftRAID window? It's still running in the MenuBar.. But wanted to confirm I can still close the app and the rebuild will continue in the background.