I am running Node.js version v0.5.9-pre on Ubuntu 10.10.

I would like to be using version v0.5.0-pre.

How do I roll back to the older version of node?

*NIX (Linux, OS X, …)

Use n, an extremely simple Node version manager that can be installed via npm.

Say you want Node.js v0.10.x to build Atom.

npm install -g n   # Install n globally
n 0.10.33          # Install and use v0.10.33

Usage:
n                            # Output versions installed
n latest                     # Install or activate the latest node release
n stable                     # Install or activate the latest stable node release
n <version>                  # Install node <version>
n use <version> [args ...]   # Execute node <version> with [args ...]
n bin <version>              # Output bin path for <version>
n rm <version ...>           # Remove the given version(s)
n --latest                   # Output the latest node version available
n --stable                   # Output the latest stable node version available
n ls                         # Output the versions of node available

Windows

Use nvm-windows, it’s like nvm but for Windows. Download and run the installer, then:

nvm install v0.10.33         # Install v0.10.33
nvm use v0.10.33             # Use v0.10.33

Usage:
nvm install [version]        # Download and install [version]
nvm uninstall [version]      # Uninstall [version]
nvm use [version]            # Switch to use [version]
nvm list                     # List installed versions