reduce - make less complex; "reduce a problem to a single question"

bowdlerise, bowdlerize, expurgate, castrate, shorten - edit by omitting or modifying parts considered indelicate; "bowdlerize a novel"

edit out, edit, cut - cut and assemble the components of; "edit film"; "cut recording tape"

condense, concentrate, digest - make more concise; "condense the contents of a book into a summary"

minify, decrease, lessen - make smaller; "He decreased his staff"