To do this with new Yamaha parts will be relatively expensive... roughly $2500 - $3000 is a good ball park. The parts, if used, could likely be had for half that, maybe less, if you can find them. FWIW, the power steering motor assembly is shared with the Grizzly ATV. The Grizzly PS ECU is a different part number, but looks the same... likely has a different assist curve for the ATV. There are tons of those wrecked... and used PS parts are readily available for them, the next issue is that they likely lead a very hard life.... and since your wife is driving it, do want to take that chance?