Manually updating the synology.me certificate

This is something I constantly need to remind myself how to do:

As my DS213J is no longer my primary NAS, it doesn't have hold of ports 80 and 443. They are now owned by my DS223. Having two Synology NAS gives me the right to have two 'synology.me' certificates, although I am not sure I really need the both of them. There doesn't seem to be a problem that one NAS holds both certificates, it is just that each one has to renew it's own certificate.

Of course, this would also apply if I decide to acquire a third, or even a fourth NAS.

With that in mind:

• Primary NAS = 1
• Older NAS = 2
• We are going to be updating the Synology.me certificate on NAS 2.

1.  Temporarily open ports 80 and 443 for 2 (This may mean closing the same ports for 1).
2.  In the Synology Control Panel of 2, make sure that DDNS is enabled and test the connection.
3.  As long as 'test connection = normal', you should be able to go to Security -> Certificate, highlight the certificate and press 'Action' and then 'Renew Certificate'.
4.  If all went well, you should be able to export the same certificate from 2 and import the 'cert.pem' and 'privkey.pem' into 1.
5.  When all is done, you can close ports 80 and 443 on 2 and re-open them on 1.
6. The new certificate seems to be valid for about three months before having to be renewed again.

Perhaps there is an easier way to do this, but this method works for me.