[chef] Best Practice Performing Upgrade and Uninstall

[Howard Zhang < >]

Hi,

I am new to Chef.

I ran over some recipes in several cookbooks maintained by the community. 

All I see is installation.  I wonder the best practice of upgrading and uninstalling software?  

Could you give me some brief idea how to upgrade and uninstall software? (please do not say " apt-get uninstall").

PS: I also ran over some recipes on OpsWorks which is one part of service provided by AWS.

Cheers,
Howard