How to make the tests pass in an elegant way? Ruby on Rails

I am writing a rails app with my colleague who wrote a lot of the tests.
He had to take a leave of absence due to a death in his family, and I am
needing helps with changing the model so that the tests will pass in our
spec file.

Here is the model:

    class Worker < ActiveRecord::Base
      attr_accessible :first_name, :last_name

      has_many :writings
    end

Here is the spec:

    require 'spec_helper.rb'

    describe Worker do
      describe "merging two workers" do
        before(:each) do
          @writing1 = Writing.create!(:writing_text => "Winner's note")
          @writing2 = Writing.create!(:writing_text => "Loser's note")

          @winner = Worker.create!(:first_name => "Jim", :last_name =>
"Sullivan", :email => "winner@gmail.com")
          @winner.writings << @writing1

          @loser = Worker.create!(:first_name => "Tom", :last_name =>
"Smithe"
          @loser.writings << @writing2

          @result = Worker.merge(@winner, @loser)
        end

        it "should return the winner" do
          @result.id.should eq @winner.id
        end

        it "should not edit the winner's name" do
          @result.first_name.should eq @winner.first_name
          @result.last_name.should eq @winner.last_name
        end
    end
    end

All of these tests are failing, and I'm not sure what to do. I don't
want to try something and accidentally break the model, as I am new to
ruby on rails. Thanks.

Edit: Fails:

Failures:

        1) Worker merging two worker should return the winner
         Failure/Error: @result = Worker.merge(@winner, @loser)
         NoMethodError:
           undefined method `merge' for #<Class:0x007fb612ee2ff8>
         # ./spec/models/worker_spec.rb:15:in `block (3 levels) in <top
(required)>'

      2) Person merging two people should not edit the winner's name
         Failure/Error: @result = Worker.merge(@winner, @loser)
         NoMethodError:
           undefined method `merge' for #<Class:0x007fb612ee2ff8>
         # ./spec/models/worker_spec.rb:15:in `block (3 levels) in <top
(required)>'

      3) Person merging two people should merge the winner's email only
if he has no email
         Failure/Error: @result = Worker.merge(@winner, @loser)
         NoMethodError:
           undefined method `merge' for #<Class:0x007fb612ee2ff8>
         # ./spec/models/worker_spec.rb:15:in `block (3 levels) in <top
(required)>'

      4) Person merging two people should not edit the winner's company
name
         Failure/Error: @result = Worker.merge(@winner, @loser)
         NoMethodError:
           undefined method `merge' for #<Class:0x007fb612ee2ff8>
         # ./spec/models/worker_spec.rb:15:in `block (3 levels) in <top
(required)>'

      5) Person merging two people should delete the loser
         Failure/Error: @result = Worker.merge(@winner, @loser)
         NoMethodError:
           undefined method `merge' for #<Class:0x007fb612ee2ff8>
         # ./spec/models/worker_spec.rb:15:in `block (3 levels) in <top
(required)>'

      6) Person merging two people should merge the notes together
         Failure/Error: @result = Worker.merge(@winner, @loser)
         NoMethodError:
           undefined method `merge' for #<Class:0x007fb612ee2ff8>
         # ./spec/models/worker_spec.rb:15:in `block (3 levels) in <top
(required)>'