diff --git a/common/static/js/vendor/CodeMirror/BUILD_README.txt b/common/static/js/vendor/CodeMirror/BUILD_README.txt
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+Instructions for creating codemirror-compressed.js (in top-level vendor directory).
+
+1. Install uglifyjs and put it on your path.
+2. In the CodeMirror directory, run "cat codemirror.js addons/* addons/dialog/dialog.js | uglifyjs > codemirror-compressed.js"
+3. Replace existing codemirror-compressed.js file with the generated one.
+
+Additions to codemirror.css are done by manually copying in the new content.