In Japan, "Boko" is onomatopoeic for punches. And "Boko-Boko" means the miserable status of a person after getting many hard punches. "Boko-Boko ni shite ageru" means "I'll force you to the miserable status of Boko-Boko"
"Miku-Miku" is a coinage worded for this song. I guess "Miku-Miku" means the happy status of a person after listening to many Miku's songs. So "Miku Miku ni Shite Ageru" means "I'll force you to the happy status of Miku-Miku".
