MARK B. answered 07/11/19
SAT Writing instructor with 16 years of highly successful experience
Never change the typos. That's a basic when quoting sources. Use the Latin abbreviation "sic" for such a purpose. So...if the source misspells something, leave it in and embarrass him--while getting yourself off the hook for poor English. Tsk, tsk... But seriously, see below for an example...
"Wow, George Washington was such a creip (sic) that I avoided him at the 1787 Constitutional Convention!"