Can I access the computer from outside?

You can access the computers graphically via a remote desktop connection. You can find instructions here: Establishing a remote desktop connection to the CIP pools EEI and WW.
If you only need one terminal, you only need to be connected to the FAU network via VPN and establish a connection to any CIP computer. You can find the DNS names or IP addresses here: https://www.eei.tf.fau.de/cip/ausstattung/#collapse_0