Kroman is ultimate Korean hangul romanization tool. It has a lot of implementations.
This is the Sublime Text 3 plugin.
The best way is installing it via Package Control.
See https://packagecontrol.io for how to install Package Control and install packages via it.
Romanize region
Romanize file
Romanize and compare
Bug reports and pull requests are welcome on Github at https://github.com/cheunghy/kroman-sublime.
Kroman is available as open source under the terms of the MIT License.