Rollback gems according to version in Gemfile.lock

I need to revert back to an older set of gem's in my dev environment. I've replaced my Gemfile.lock file with the old versions I need.

I thought I could just replace the Gemfile.lock and bundle install but that doesn't seem to work. Because when I do that and then run bundle install and then check the gem version number I get the same versions I had before.

One of the gems I need to downgrade is the rake gem. The version I need is 11.1.2 but currently when I do gem list I get rake (12.0.0, 11.1.2, 10.4.2)

So how can I revert rake and all the other gems, back to their previous versions?