OK, I have engineering education myself and my dad was an electrical engineer, so here are the facts.
If he is really interested in EE as a career, Step One is to get as much math as possible. He needs the highest level available of Algebra 1, Geometry, Algebra 2, and Trigonometry. He needs either an in-depth Pre-Calculus course or a version of Calculus 1 that covers at least a full year (to cover some of that Pre-Cal), or both. He needs to take the AP Calculus test if at all possible, and preferably the BC level. If his math is not up to this level, then EE is not the best degree for him -- maybe he should look at other engineering fields.
Step 2 is to get as much physics as possible -- if at all possible a two-year in-depth program, one year general and one year AP Physics, highest level available.
Step 3 is to take as many classes as possible in related topics, chemistry definitely required, classes in engineering and robotics and computers (not just using programs, but writing programming and/or repair) very strongly recommended.
Now, the question arises of how badly dyslexic he is. All of the above require a certain amount of reading and a high degree of exactitude. If he is not up for this, other technical careers might be a better fit for him.
If he is capable of being both fast and exact in math, then you can relax a little about the humanities courses; engineering schools will expect basic university level work, but engineers spend 90% of their time on the math and science.