Police said CCTV revealed that, after getting off the tram, Hughes opened the packet of knives.
After disposing of three of them, police said he “lay in wait for someone to walk past him”.
Officers said Hughes then followed and attacked Ms Hodgkinson from behind as she walked past on her way to meet her mother.
Passers by and the emergency services battled in vain to save her.
Det Ch Insp Danny Lee said: “Michelle’s death has left a void in her family, and nothing will fix the pain they are feeling.
“I hope that they can gain some form of closure and justice from the sentence passed today.”
He added: “I’d like to thank the members of the public who rushed to Michelle’s side and the first responders – paramedics and response police officers – who also attended the scene to give CPR in an attempt to give her the best possible chance of life.”
In a previous statement, Ms Hodgkinson’s family said: “Everyone who knows Michelle are still in utter shock at the attack she endured and how horrific her last moments were.
“Words cannot describe how much she will be missed. Our biggest cheerleader, our confidant, our rock – she will never be forgotten.”
