DO NOT DO THAT. Ameriacn universities, especial top ones, count this kind of behavior as cheating. Right now due to the bad credit of Chinese students, most university will double confirm your transcript with your college.
You'd better give up any idea to modify your transcript. Do not take any risk of this issue. The schools still can kick you out even they admit you, when they find that your transcript has something wrong later. Most of the top30-50 bschools are in the top American universities, they are alert to Chinese students' transcript after they found many Chinese students made the fake transcripts. Cheating is a big issue in US, especially most bschools tried to emphasize the ethical course now. Try to find some other way to compensate your low GPA. BTW, if you can modify the original GPA record in your college computer, it may work. But I still do not recommend this way. It is very weird if you delete some math class, this would make your transcript big difference from others.
Actually, one way to solve the problem is that you can inquire the school and give them reasons to delete several courses from your GPA. After you get approved, notice: only after the schools approve you do so, you can do that.
Otherwise, it's dangerous. Not only dangerous during the admission procedure, but also dangerous after you are admitted. There are already several examples who are repatriated to China, even though they had already studied in US for a couple of years and get high marks.
If you only delete not-so-important courses, you might get away from that. But, to me, it still sounds dangerous, because school will count your credits in university.
I don't think the school will check the transcript for every admit students. But it is quite possible that they do spot check, or if someone send an email saying' I know this person forged his transcript, blah blah blah...' A famous case is when UCLA expelled a student in Biological(?) department from Wuhan university, I heard it is because a classmate sent an email to the department. Another case I heard of is HBS expel a student who forged transcripts and diploma(??) Not sure how he was caught. And then a couple of years, wharton kicked out a chinese woman who forged the most part of her employment history. That said, I do not think it is worth the chance. It is a very serious matter.