You just want to open the plugin yeah?
No troubles mate, I assume you are starting out. Cubase can look tricky at first!
Firstly make sure you have created an Instrument track. It will prompt you asking which VST Instrument to add so click the drop down menu and find and click Massive. Then in the right you will get an overview of the current layer and about halfway down there is a tiny thing which looks like a box with an arrow. Click that and theres massive!
