EXCLUSIVE: Mama June's weight loss surgeries revealed -- how she went from 460 pounds to a size 4

Mama June's much hyped stunning physical transformation is the result of not only multiple surgeries, but of plenty of hard work and an entire mental overhaul, her daughters, Alana and Lauryn Thompson, tell ET exclusively.

ET sat down with 11-year-old "Honey Boo Boo," 17-year-old "Pumpkin" -- as they're known to Here Comes Honey Boo Boo fans -- as well as Mama June's show trainer, Kenya Crooks, on Wednesday, when they dished about her dramatic weight loss. Mama June's journey is being chronicled on her new WE tv docu-dramedy, Mama June: From Not to Hot, which debuts on Friday.

"She had gastric sleeve back in May of 2015, and then she slowly started losing weight, and the reason she got the gastric sleeve was because she hit a plateau -- she couldn't lose any weight," Pumpkin tells ET's Jennifer Peros, referring to the procedure that makes a patient's stomach smaller. "And then it came to a point where [the trainer] had to step in because she hit another plateau with the gastric sleeve, and wasn't losing any more weight."

See photos of Mama June:

WATCH: Mama June Drops Down to a Size 4 After Weighing 352 Pounds, Her New Show Teases

Mama June, 37, also got surgery to remove excess skin after dramatically dropping pounds.

"Her stomach started looking gross," Pumpkin candidly says. "It was hanging from where she lost so much weight, and her arms and her chin, so she got [the skin on] her stomach removed."

The mother of four later got surgery on her breasts.

"She got her boobies done," Pumpkin reveals. "She got them from a 44 long to 36 up."

Mama June started her weight loss journey at 460 pounds, and a teaser for her new reality show suggests that she's now down to a size 4. However, Pumpkin says her mom still struggles with seeing herself as a much heavier person.

"I think that her biggest thing [she has to] overcome is that fact that she still thinks of herself as a bigger person, because, even to this day, like, a couple of days ago we had a conversation, and ... she looked in the mirror and was like, 'I'm still fat,'" Pumpkin shares. "And I guess because she's seen herself as a bigger person all these years, she doesn't realize how small she is."

"That's what she's used to doing, and when you're a bigger person, that's how you disguise all of that -- through wearing bigger clothes," Crooks weighs in. "So, now, we're having to transform her mind even more so ... because she has curves now, she looks awesome."

Another huge challenge? Getting Mama June to stay in hiding until the show is ready for her big reveal.

"It is very hard because mama, she is a very stubborn person, and she wants to do everything," Pumpkin explains. "She's like, 'Alright, I've got to go to the store,' and we're like, 'Mama, no, you need to stay in the house because if somebody gets a picture with you...'"

See photos of Mama June and Pumpkin:

"Even if she does go out, she has to be, like, suited up," she adds about her mother's disguise.

Most important, Mama June's daughters says she is much happier after her significant weight loss, and feeling much more confident.

"I kind of didn't want her to do it before, but after she did it, I'm very happy," Honey Boo Boo acknowledges, referring to the risks of weight loss surgery.

"I'm not trying to be all R-rated or whatever, but, she'll walk around the house in a pair of underwear!" Pumpkin later jokes about her mom's self-confidence these days. "I'm like, 'June, put your pants on, put your pants on!'"

WATCH: Mama June Documents Extensive Plastic Surgery, Body Transformation in New Show 'From Not to Hot'

The network has called Mama June's weight loss "the most shocking transformation in reality TV history."

"I'm changing my body and my love life," Mama June says with determination in one teaser. "I'm about to start the biggest transformation of my life. This surgery is the scariest thing I've ever done, but there is a skinnier person inside of me."

Mama June: From Not to Hot debuts Friday, Feb. 24 at 10 p.m. ET/PT on WE tv.

Watch the video below for more on Mama June's epic body transformation.