For UCB:
Admission via a change to the College of Engineering is very competitive and highly unlikely, and students should not count on admission through this method. Through direct freshman and transfer admissions, we admit the maximum number of students possible each year. Students interested in studying Engineering at UC Berkeley should apply directly to the college as freshman or transfer applicants. Please contact an academic advisor to determine if a change of major is possible
For UCLA here is the link but again highly competitive with no guarantees. https://www.seasoasa.ucla.edu/ls-to-engineering/