I'd like to upgrade from 1.1.6 to 1.2.1, one big feature in 1.2 is that it can have multiple tokens in one node. but there is only one token in 1.1.6. 

how can I upgrade to 1.2.1 then breaking the token to take advantage of this feature? I went through this doc but it does not say how to change the num_token

http://www.datastax.com/docs/1.2/install/upgrading

 Is there other doc about this upgrade path?

Thanks,

Daning