Firstly, you have 10Gb NIC in both nodes for cluster interconnect. Then you could install all new cDOT image into your FAS2240. Finally, setup your cluster mode in first node and join second node. Done. Weir
Yes they can be directly connected however you also need the cluster license. the process is documented in a kb (not one I have on the top of my head) but the high level is to perform an "option 4" in the boot menu and reinstall ontap. The KB has some redundant steps however if you follow it you should be golden.