I updated my JHipster installation as per this page by running the command
npm update -g generator-jhipster
But to update my application I
Following [jhipster releases] (https://jhipster.github.io/2015/05/31/jhipster-release-2.14.2.html): How to upgrade
Update your version of JHipster with:
npm update -g generator-jhipster
And then you can update your project when you run again
yo jhipster
You can also update your entities by running again the entity sub-generator, for example if your entity is named Foo
yo jhipster:entity Foo