Need a shopify Expert

Hello: In this shopify store When inventory reaches 0 the variant should read... “variant-Sold Out-Notify Me” Back in stock app is already installed and button is already created. Only the variant view needs adjusting both in quick view and product view for selecting. Remember- the functionality is perfect as it was before. The only change I would like is for the variants to show “variant-Sold Out-Notify Me” in drop down exactly like fashionova. The Price 8$ is fixed Kindly Look at attached images!