Upgrade SharePoint Content Types / Site Columns declaratively in SharePoint hosted apps

Hi!

I have a question where I was unable to find any official guidance for. I have created a SharePoint hosted APP where I have multiple site columns and content types (declared in XML). The APP installs and functions just fine. 

Now I have a requirement to change a site column (Choice field, just add some more choice values). I was able to update the site column but the changes will not be reflected on the list column (I think because there no way to push the changes).

So is there an "official" way of changing site columns?

Any help is appreciated!
Thx!