Manually upgrade jenkins version

To manually upgrade jenkins, first you need to connect to the jenkins server and then become root:

Connect to server

ssh <user>@<jenkins_server>

Become root user

sudo su

Go to jenkins directory where the war file exists

cd /var/lib/jenkins

# or

cd /usr/share/jenkins

Archive current version of jenkins.war file

gzip jenkins.war
It will create jenkins.war.gz file and will delete jenkins.war file

Download latest version of jenkins.war file

wget http://updates.jenkins-ci.org/download/war/<version>/jenkins.war

Restart jenkins

/etc/init.d/jenkins restart

Now you need to wait a few seconds to restart jenkins and then you'll see the version was upgraded