Blender 2.79 / 2.80
Older versions of Meshlab might work but the addon is only tested with Meshlab 2018
Option 1: You can uncompress the downloaded zip file to your Blender user/addons folder. Once the addon is copied there, you need to restart Blender or press `F8` to refresh the addon scripts.
Option 2: Open your Blender preferences. Then open the `Add-ons` tab. You can use `Install addon from file` in that tab to install the zip file.
Once installed you need to enable it from the `Add-ons` tab. You can just search for `basemesh` in the search bar. Then click on the checkbox and expand the addon for adding the required settings like `Meshlab 2018 folder` Once done save your preferences settings.