Installing an extension tool on Visual Studio is quite easy; from the topmost menu, select Tools | Extensions and Updates, and then click to the Online item tree to the left. Once there, start a search using the LESS Compiler keyword and locate the LESS Compiler by Mads Kristensen:
During the installation phase, you will be asked to quit and restart Visual Studio, so be sure to save everything before doing it.
Starting with the 2017 release, Visual Studio won't prompt you for an immediate restart like it used to do in the past; it will just inform you that the new tool(s) will be installed once all VS windows are closed, ...
