The act requires three years of postsecondary engineering education, or three years of engineering experience, or a combination of the two. Lets say you had a family member with a small engineering practice who took you on right out of high school and had you doing calculations, code review, spec review, taking measurements in the field, etc., all under supervision (an apprenticeship, if you will) that would start the clock and at the end of 3 years you would need to meet the 6-year requirement. See Article 4 part 6751 shown here.
There are indeed a some waivers, but they are fairly onerous without an ABET sanctioned degree. This is the latest California Board of Professional Engineers and Land Surveyors (BORPELS)FAQ.