Rails 3 #update_attributes

I'm working on a Rails 4 app that was previously upgraded from Rails 3. I haven't worked much Rails 3 before. I came across this something like this user.update_attributes({ attr => bulk_update_params[attr] }, :as => :admin). Rails 4 currently complains that update_attributes only accepts 1 argument and not 2.

I tried merging the as: :admin by doing user.update_attributes({ attr => bulk_update_params[attr] }).merge(as: :admin) but then i get greeted with something like "as" is not a known attribute".

Not entirely sure but how do I deal with the as: admin part? Is it safe to remove it entirely or there's a way to pass as: :admin to the original user.update_attributes({ attr => bulk_update_params[attr] }, :as => :admin) in Rails 4?

I think it has something to do with attr_accessible and strong_params just not sure how to work with it in Rails 4 now. Any ideas?