Link to general update document

doc/gitlab-geo/updating_the_geo_nodes.md

@@ -4,25 +4,9 @@ In order to update the GitLab Geo nodes when a new GitLab version is released,
 all you need to do is update GitLab itself:
 
 1. Log into each node (primary and secondaries)
-1. Upgrade GitLab
+1. [Update GitLab](../update/README.md)
 1. Test primary and secondary nodes, and check version in each.
 
----
-
-For Omnibus GitLab installations it's a matter of updating the package:
-
-```
-# Debian/Ubuntu
-sudo apt-get update
-sudo apt-get install gitlab-ee
-
-# Centos/RHEL
-sudo yum install gitlab-ee
-```
-
-For installations from source, [follow the instructions for your GitLab version]
-(https://gitlab.com/gitlab-org/gitlab-ee/tree/master/doc/update).
-
 # Upgrade to 9.0.x
 
 > **IMPORTANT**: 9.0 requires manual steps in the secondary nodes,