> What the Higgs mechanism does is add effective mass even to particles which are intrinsically massless, so long as they couple to the Higgs field. For the standard model, that means leptons, quarks, and the W and Z bosons.

this was sloppy: the W and Z bosons have mass because they mix with the Higgs field (this is the Higgs mechanism, properly speaking), while the mass acquired by leptons and quarks is due to interacting with the remaining Higgs component in the usual way.