Sleepaway Camp 2

T.C., the head counselor at Camp Rolling Hills, is at a campfire with the male campers Sean, Rob, Anthony, Judd, Charlie and Emilio. Also there is Phoebe, who has sneaked away from her cabin to be with the boys. As Phoebe tells the story about the killings of the previous film at Camp Arawak, her head counselor Angela appears and forces her to go back to the cabin. After the pair get into an argument, Phoebe becomes lost, only to be attacked by Angela who hits her over the head with a log before cutting her tongue out.
The next day, the campers in Phoebe's cabin, including Molly, Ally, Mare, Demi, Lea and twins Brooke and Jodi, question Angela on the whereabouts of Phoebe, however she tells them she had to be sent home due to bad behavior. At breakfast, the head of camp Uncle John gives Angela "the counselor of the week award". Afterwards, Angela discovers Brooke and Jodi smoking marijuana and drinking, so she interrupts them. Later, Brooke awakens on a grill only to see the skeleton of her already cremated sister. Angela then pours gasoline over Brooke and burns her to death. Meanwhile, Molly and Sean start a relationship, despite Ally's attempts to seduce Sean.
That night, the boys throw a panty raid in the girl's cabin until Angela comes in, throwing them out. Later, the girls raid the boys cabin. T.C allows the fun to go on, but Angela appears and witnesses Mare showing off her breasts. Mare decides she wants to leave the camp, so gets Angela to drive her. While traveling, Angela gives Mare one last chance to apologize, however when she fails to do so Angela murders her with an electric drill. The following day, Angela discovers Charlie and Emilio looking at naked pictures of various campers they had taken in secret. That night, the girls go camping, giving Anthony and Judd a chance to scare Angela, dressed as Freddy Krueger and Jason Voorhees. The plan backfires however, when Angela dressed as Leatherface slashes Anthony's throat with a clawed glove before murdering Judd with a chainsaw. After finding out Ally has walked away to have sex with Rob, Angela plans to murder the pair but her plan fails.
The next day, Angela sets up a trap for Ally, leaving her a fake note from Sean. Ally goes to meet Sean, but instead meets Angela, who stabs Ally in the back before forcing her down the outhouse toilet hole, drowning her in feces and leeches. That night, Demi reveals to Angela that she phoned the families of the girls who had been sent home by Angela, but they denied the girls being sent home. Realizing she could be caught, Angela strangles Demi to death with a guitar string, before stabbing Lea to death when she finds Demi's body. The next day, Uncle John and T.C fire Angela for not telling Uncle John about sending the many campers home.
Feeling sad for an upset Angela, Molly and Sean go into the woods to cheer her up. However the pair discover the bodies of the other campers in a cabin, before Angela ties them up. Back at camp, Rob tells T.C the whereabouts of Molly and Sean, prompting T.C to go off to fetch them. He enters the cabin, only for Angela to throw battery acid on his face, killing him. Sean realizes Angela is Peter Baker, the murderer from the previous movie. Angela reveals that after two years of electroshock therapy and a sex change, she was released for having good records from doctors. She then proceeds to decapitate Sean. Angela leaves the cabin, allowing Molly to free herself and upon Angela entering, knock her out and escape. Angela chases after Molly through the woods, who finally falls off a rock and is presumed dead.
Later that night, camp counselor Diane discovers the dead bodies of Charlie, Emilio, Uncle John and Rob, before she is stabbed to death by Angela. Meanwhile, Molly regains consciousness and begins to make her way out of the forest. Angela hitchhikes with a truck driver, who quickly annoys her, making Angela stab her to death. As Molly makes it out of the woods, she finds the truck, but is horrified to find that Angela is the driver. The movie ends with Molly screaming and presumably killed by Angela.

Question: How does  Demi dies?
Answer: Angela strangles Demi to death with a guitar string