How do I downgrade node? There's no brew versions command!

I'm using brew. I have node installed. I want to use an earlier version of node.

Online, I find instructions such as, for example:

cd /usr/local/Library/Formula
brew remove node --force
brew versions node
git checkout 83988e4 /usr/local/Library/Formula/node.rb
brew install node

The problem I have with this is that brew doesn't seem to have a versions subcommand:

$ brew versions node
Error: Unknown command: versions
$ brew --version
0.9.5

I'm new to brew. Do I need to enable the versions subcommand somehow? Should I use a different subcommand instead?

I'm running OS X Yosemite (10.10.1); brew 0.9.5.