Upgrading Ember Web Application from 1.2.2

The Ember web application currently in our production environment has the following versions.

• ember.js - 1.2.2
• ember.data - 0.13

I've found upgrade notes from ember 1.10 onwards in the following guide but the version of ember in our application is much older.

Guide: http://ift.tt/1G8PK0G

Ideally, the application needs to be upgraded to 1.10 then following this guide to 1.13 and then progressing upwards to 2.0+ etc.

Are there any known issues with upgrading the application from a low version of 1.2.2 to 1.10. Ember-data will need to be upgraded in parallel, I assume but not too sure on when to upgrade each.

Finally, is there any possible way to add the ember-cli into an already existing application? If so, what ember-cli version should be added and when, to upgrade wit ember.js and ember-data.js.