Walking up to the house in the dark, Grant was carrying a gun by his side when they knocked on the door asking to speak to the woman.
When the pair demanded money, it was said she was adamant she owed the men nothing.
Grant then lifted the firearm, pointing it at the victim, and warned her not to make him angry because she wouldn't like what would happen.
The men left when she promised she would get the money to Grant, and she provided a contact number.
Before driving away, Grant pointed the gun out of the car window, firing a "warning shot" into the air.
The court heard the alleged debt was drug-related, and the offending itself was motivated by his own addiction to meth and from mixing with gang members.
Grant then began threatening the woman over texts, demanding more money and, this time, methamphetamine.
Sobering up while behind bars, Grant told report writers if he was to stay away from the gang and drugs, he would stay crime-free.
Spending nearly seven months remanded in custody, prison provided a "turning point" which solidified his intentions for change.
Judge Mill said one of the two reports written before sentencing outlined a man who still partly blamed his victim for what happened and minimised his own actions.
It said if he was to go back to his old lifestyle, there was a high risk he might reoffend.
What was "puzzling" for Judge Mill, however, was that Grant had many traits of being a "good young man", but falling in with the wrong crowd and taking drugs had set him on a path of crime.
Judge Mill said Grant's family had noticed a huge change in attitude and behaviour since his release on bail, and acknowledged a genuine attempt at rehabilitation since his arrest last year.
"In fact they're quite proud of how you've turned things around," Judge Mill said.
"[You are] genuinely and consistently trying to put your life back together – so I think there is hope."
Grant's mother and partner attended this morning's sentencing in support.
When handing down his sentence this morning, Judge Mill said Grant had earned his less punitive sentence of home detention, but not without challenging him.
"The challenge for you is to remain out of trouble and remain on the track you're on now," Judge Mill said.
He said he hoped he would never see Grant before the court again and this chance was an opportunity to prove himself.