The extract may be good if it's "dry extract" and not "liquid extract", but the yeast should go in the trash and if there are any hops I'd say trash them too if they are over a year old as well. You should be able to get fresh hops and yeast from any brew shop, or online, for about $10.
What type of equipment is in the kit? I'd personally not even risk the extract, and if you have all the equipment to brew, just go buy an extract kit and start with that. Just my $0.02