How to swap "-" with "+" for Accordion item?

If you want to swap how "+" and "-" works for accordion, please paste below css into Theme options > Layout > Custom CSS section:

.mfn-acc .question .title > .acc-icon-plus { display: block; }
.mfn-acc .question .title > .acc-icon-minus { display: none; }
.mfn-acc .question.active .title > .acc-icon-plus { display: none; }
.mfn-acc .question.active .title > .acc-icon-minus { display: block; }