I have never had this happen to me yet, but see if you can have someone push downward on the hood while you jiggle the release handle every which way with vigor.
Find a large assistant as you will be trying to compress the rubber bumpers under the hood nose so that there will be wiggle room for the latch to move and maybe release.
If that doesn't work, remove the bolts, rubber pad and shims from under the radiator support.
