How do you unlock Marcus Fretshredder in Guitar Hero Van Halen?

Earn 55 stars on the Guitar career

Shirley C. Excatly like Marcus Fretshredder except earn 55 stars on the BASS career

Matty C. Excatly like Marcus and Shirley except earn 55 stars on the DRUMS career

Riki L. Excatly like Marcus, Shirley, and Matty except earn 55 stars on the VOCALS career