Depending on your car you may be able to see the back of the washer jet by raising the hood or you may have to release the under hood covering to get access . Get someone to operate the washer and watch where the leak is from, probably a cracked jet body from what you describe. To release ,disconnect water pipe and any electric wiring attached then release the retaining lugs ,push upwards and withdraw from the bonnet, then fit new jet you already bought from dealer.
Geo.