This is just an informative post.

The ReadyNAS will have it's own IP address.
After plugging it to the server, download Chrome on the Server and browse to https://IP ADDRESS/admin and use admin and password.
Disable X-RAID if you want
Create a group and use default values supplied. Copy the IQN that gets shown when you try this.
Go to iSCSI initiator and add this IQN as your taget > Connect to it.

After you are connected, add a new LUN and assign your group to the LUN.
Now, go to Disk management and you will see your drive > Initialize > Format and start using it !