I've never looked into doing this on a 4Runner, but many times the stalks are mounted in a sort-of collar below the steering wheel--remove the wheel, disconnect the electrical connections, and swap out the broken unit. Usually you'll need a special puller to remove the wheel, but it's not a complicated procedure. You probably have an airbag--that's the item that requires the most caution--no shortcuts messing with those. Check the service manual section for 3rd Gens, or ask around in the 3rd Gen thread section--this section (General Discussions) may not be the best place to ask.