Here is a simple guide on how to load and start using the ERA Bundle audio effect plug-ins in REAPER:
Step 1: Verify that the plug-ins are installed in the correct locations
AU ➝ /Library/Audio/Plug-Ins/Components
VST ➝ /Library/Audio/Plug-Ins/VST
VST(32-bit) ➝ C:\Program Files (x86)\Steinberg\VstPlugins\Accusonus
VST(64-bit) ➝ C:\Program Files\Steinberg\VstPlugins\Accusonus
AAX ➝ C:\Program Files\Common Files\Avid\Audio\Plug-Ins
Step 2: Open Reaper and create or open a project from the file menu
Step 3: Create an audio track by selecting from the menu Track ➝ Insert new track (omit this step if its a preexisting project)
Step 4: Open the mixer by selecting from the menu View ➝ Mixer
Step 5: Locate the Track Insert FX slots section on the top part of the mixer view, and click on a slot to open the new FX window.
Step 6: Browse and load the plug-in of your preference by double-clicking on it.
Done! Now you are ready to start using your plugins.