After Effects installation
Download the plug-in installer for your particular platform from the Download Area and run it. The plug-in is compatible with After Effects CS3, CS4, CS5, CS6 and CC. There are plug-ins available for Windows and Mac OSX. You can download the plug-in from the After Effects plug-in for Maxwell page.
For plugin compatibility with After Effects versions, please see the Plug-ins page.
Windows
Run the installer. The installer should locate your After Effects installation automatically. If not, browse the location(s) where After Effects was installed.
After Effects CS5 plug-in installation folder usually is C:\Program Files\Adobe\Adobe After Effects CC\Support Files
Mac OSX
Unpack the files. Copy the MXI.plugin to the After Effects format plug-ins directory, and the mxiMixer.plugin file to the After Effects effect plug-ins directory.
After Effects CS5 format plug-ins directory usually is /Applications/After Effects CC/Support files/Plug-ins/Format
After Effects CS5 effect plug-ins directory usually is /Applications/After Effects CC/Support files/Plug-ins/Effects
Remember that you should have writing permissions and Administrator privileges to install the plug-ins.