Install (Maya):

Download maya_cast_plugin.zip and place the files in the zip in the following directory depending on your OS and Maya version:
- 32bit Windows: C:\Program Files(x86)\AutoDesk\Maya-ver\bin\plug-ins\
- 64bit Windows: C:\Program Files\AutoDesk\Maya-ver\bin\plug-ins\
Next, you must open the plugin manager using Window->Settings/Preferences->Plugin Manager once there find castplugin.py and check off the following:
- [castplugin.py] Loaded (Loads the plugin)
- [castplugin.py] Auto load (Loads the plugin every launch)

Install (Blender):

Download the blender_cast_plugin.zip file.
Open Blender and select Edit -> Preferences -> Add Ons -> Install and select the newly downloaded zip file.
In the search bar in the upper left, search for Cast. If no results are found, try enabling the Testing or Community supported level below the search bar.
Enable the plugin by clicking the checkbox next to the plugin name.
Select Save User Settings in the lower left and close the window.

Full Changelog: v1.77...v1.78