Find which division your desired majors are in. Then find out the procedure for changing to that division:
https://engineering.berkeley.edu/academics/majors-minors/change-major
https://ls.berkeley.edu/advising/academic-progress/changing-status/change-college-ls
https://chemistry.berkeley.edu/ugrad/current-students/change-of-college
https://nature.berkeley.edu/advising/frequently-asked-questions
https://ced.berkeley.edu/students/undergraduate-advising/forms-documents/
https://haas.berkeley.edu/Undergrad/ucb_admissions.html
Note: some majors may have higher standards than their divisions. For example, the majors in economics, statistics, psychology, and some other popular subjects have higher grade/GPA requirements than the L&S division that they are in.