While feeding Bruce Saunders into a woodchipper, Peter Koenig ensured his friend's legs were exposed so it looked like an accident, a court has heard.
Gregory Lee Roser, 63, is on trial for murder after Mr Saunders, 54, died while working on a property north of Brisbane in November 2017.
Sharon Graham, 61, asked Roser and Koenig to kill Mr Saunders and make it look like an accident in a bid to claim her ex-partner's $750,000 life insurance policy, the Crown alleges.
Police footage has been shown to the jury of Mr Saunders' legs protruding from a woodchipper at the Goomboorian property near Gympie after clearing trees with Roser and Koenig.
Roser killed Mr Saunders by repeatedly hitting him with a metal bar before they carried the body to the chipper, Koenig told Brisbane Supreme Court on Wednesday.
Koenig said he then used a branch to push Mr Saunders into the machine but decided to stop with the legs still sticking out so it appeared to be an accident.
"Just to leave a bit of Bruce there I suppose ... for the police to see it," said Koenig, who pleaded guilty to accessory after the fact to murder in June.
He said he couldn't ring triple zero because his hands were shaking but Roser was able to call Graham before handing him the phone.
Koenig agreed he told Graham: "Bruce is no longer with us, job's done".
Koenig said Roser then began screaming "something like ... oh Bruce, what have you done" to make neighbours think there had been an accident.
Roser told him they would have to get their "story straight" before police arrived, Koenig said.
At first Koenig did not believe Mr Saunders would die and therefore did not warn him, saying it wasn't the first time Graham had asked him to kill a man for money.
He said Graham requested he murder another ex-partner, Barry Collins, earlier in 2017 and "make it look like a truck accident".
"Because he had a lot of superannuation money, she was the beneficiary to it," Koenig said.
"I just agreed with it to keep her happy (but) no (didn't do anything) - he is still alive today."
Koenig said he also refused to kill Mr Saunders, who he considered a friend.
When they had finished clearing trees on the property for a third straight weekend without incident, Koenig thought "beauty, it's not going to happen", the court heard.
But as they left, Koenig said he noticed Mr Saunders fall to the ground.
"I turned around and he (Mr Saunders) was lying on the ground on his back... he was twitching," he said.
"Greg was there with a bar and struck (Mr Saunders) a couple more times in the head.
"I said 'what the f*** are you doing?' and he said 'I think I have killed him' and 'he's dead'."
Koenig said he helped carry Mr Saunders over to the chipper because Roser had a bad back.
Koenig agreed that he owned the metal bar used by Roser and put it in his truck afterwards.
Koenig had been in an intimate relationship with Graham who was dating Roser at the time of her ex-partner Mr Saunders' death, the court heard.
Graham has been accused of being in a "love quadrangle" with Roser, Koenig and Mr Saunders, plotting the latter's murder for months.
Graham has pleaded not guilty to Mr Saunders' murder but Justice Martin Burns on Tuesday ordered she be tried separately from Roser.
Koenig confirmed he had exchanged pornographic images with Graham up to January 2018 and over five years catalogued about 1000 pictures of her on his phone in folders under names such as "hard core", "great times", "breast" and "trouble".
But Koenig denied that he murdered Mr Saunders because he was "obsessed and infatuated" with Graham, saying he "liked her" and they were "brother and sister basically".
"I did not kill him," Koenig said.
Roser's trial continues.