They’ll take another stab at it.

A Long Island teen convicted of slaying his retired NYPD stepfather with a samurai sword in 2005 has been granted a new trial by the state’s highest court.

Zachary Gibian, now 23, was convicted of murder in 2007 for the brutal slaying of Scott Nager, 51, as he slept on a couch in their Hauppauge home. Gibian is currently serving 25 years to life.

But the high court affirmed an appeals-court ruling that tossed the conviction because of errors by Judge Robert Doyle during Gibian’s trial, including the barring of testimony that pinned the murder on Gibian’s mother.