I have a machine with Ubuntu 12.04 and have installed Jenkins ver. 1.424.6 using apt-get based on this guide
You can overwrite the existing jenkins.war
file with the new one and then restart Jenkins.
This file is usually located in /usr/share/jenkins
.
If this is not the case for your system, in Manage Jenkins -> System Information
, it will display the path to the .war
file under executable-war
.