Use this download link below to download sound files and all you have to do is drag and drop each one separately into the Sounds folder on WoW (File Location shown below)
Link - https://we.tl/t-bqyVwiFlQ8
Program Files (x86)\World of Warcraft\_retail_\Interface\AddOns\WeakAuras\Media\Sounds
Note - If you would like to customize some stuff just read information tab on the weak aura you'd like to change.