Updating Rails

I have a project that was created using Rails 2.0.1 and is now on a computer which has Rails 2.1.0 installed. Is there an easy way to update the project? If I run "rake rails:update" in the root directory of my project (which seems like what I want to do), it complains that the 2.0.1 gem is not installed.

Thanks in advance for your help.

Have you tried to install Rails 2.0.1 and then run the command again?

Did you change environments.rb to rails 2.1 ?

first: change in environment.rb ,set 2.0.1 to 2.1.0 second: rake rails:freeze:edge TAG=rel_2-0-1, old project use old rails, that's my idea third: change back 2.1.0 to 2.0.1 the project use rails in vendor/rails and new and old project both ok.