I just loaded ezdrummer into my Cubase Artist 7 .How to I access it from Cubase?
You did not list any system or software specs or explain exactly what your issue is…
Generally speaking…
The exdrummer.dll file that is on your computer must be installed in a location where Cubase will scan and “see” it. These locations are found in the Cubase devices>plugin manager menu. You can either add the location to the VST2 plug in folder list or move/copy/paste the .dll file to one of the locations already listed in the VST2 plugin folder list.
After that restart Cubase to ensure it scans for the new exdrummer.dll (or you can hit the “refresh” button in the VST2 plug in folder menu).
Ezdrummer should now be available to use with any “instrument” or “midi” track.
If you need more help please supply your computer and software specs and list specific questions.
Good luck.
Regards 
Thank you