Hire a keyboard player. The keyboard player should play simple chords and leads using synthesized string sounds.
Use disco-influenced beats. This is a New Wave music staple. Preferably, generate the beats with a drum machine.
Play guitar with heavy distortion. Heavily distorted guitar is a staple of heavy metal music.
Play fast guitar solos. Fast guitar solos are very common in heavy metal music.
For a New Wave vocal style, sing in a monotone using a clipped, clear voice. Sing about themes like relationships and technology. For a heavy metal style, growl and bark or sing with a screech. For heavy metal lyrical themes, sing about war, death and evil.
Write long, complex songs for a heavy metal-influenced song structure. Write simple, shorter songs for a New Wave structure.