Installinh SP2

I'd like to install SP2 for Zoho but when I type ./UpdateManager.sh

This is the message I have:

Exception in thread "main" java.awt.HeadlessException:
No X11 DISPLAY variable was set, but this program performed an operation which r equires it.
at java.awt.GraphicsEnvironment.checkHeadless(Unknown Source)
at java.awt.Window.<init>(Unknown Source)
at java.awt.Frame.<init>(Unknown Source)
at java.awt.Frame.<init>(Unknown Source)
at javax.swing.JFrame.<init>(Unknown Source)
at com.adventnet.tools.update.installer.UpdateManagerUI.<init>(UpdateMan agerUI.java:1051)
at com.adventnet.tools.update.installer.UpdateManager.init(UpdateManager .java:123)
at com.adventnet.tools.update.installer.UpdateManager.main(UpdateManager .java:354)

I don't have X11 installed on my redhat 7.2 server, I only use command line, so how can I install SP2?

Best regards