At one point Mr Skorek looked at Herewini's crotch and later asked him to go for a walk. Samuels followed them and assaulted Mr Skorek.
As Mr Skorek lay prone on the ground he was kicked and punched in the head and body by the group for about 20 minutes.
They stole Mr Skorek's backpack, containing a knife with a five-inch blade, leaving him unconscious in a pool of blood. They later returned and Samuel and Herewini stabbed Mr Skorek in the face and chest before Herewini cut his throat, inflicting a six-inch open wound.
In court, Edwards read out a letter he had written to Mr Skorek's daughter, saying how sorry he was.
"If I could make time rewind, I would turn back the clock," he said.
He had nightmares and it was "always the same dream", he said.
His lawyer, John Bergseng, said an emotionally immature Edwards was pressured into taking part in the attack.
Edwards had been smoking cannabis since he was 7, drank heavily and had given up on education. However since being in custody he had made good progress, he said.
Glen's lawyer, Max Simpkins, told the court his client had a difficult upbringing.
When Glen was 5, his father was murdered and the family moved to Rotorua. Glen was bullied at school and became caught up with negative influences.
He said Glen had been crying at the outset of the attack on Mr Skorek and did not want to take part. Mr Simpkins said Glen kicked Mr Skorek in the body and stood on him, however did not kick him in the head as the others had.
Glen had been on electronic bail since last April and had made exceptional progress, Mr Simpkins said.
A jail term would be counter-productive to Glen's rehabilitation, he said, and requested the court impose home detention.
However, Crown prosecutor Amanda Gordon said violent offending by young people was prevalent and a deterrent message had to be sent.
Justice Collins accepted both boys were susceptible to peer pressure by the older men. He gave them a discount for their age, genuine remorse and rehabilitative prospects.
"You have both shown considerable abilities to make something of your lives," Justice Collins told them.
"I sincerely hope that both of you will do all you can to put this terrible crime behind you."