Migrating to Ember 1.1x - Getting rid of ObjectController + ArrayController design

I'm currently using Ember 1.8 and planning to migrate to Ember 1.12. I have gone through many videos and understood that I should follow Component based approach and get rid of ObjectController & ArrayController slowly. But, I couldn't able to crack down how to replace my ObjectController + ArrayController design with Component design. Any pointer will be really helpful.

The main reason I opted for ObjectController + ArrayController design at the first place was to do item toggle(expansion & collapse of item list). Kindly suggest how to do the same using components.