How can I modify the 'buy button' code to use a photo instead?

[Wineaoeasy]

Hi. 

We use 'buy button' on our website. 

We keep inventory on Shopify, create a buy button for products. We copy and paste the buy button code and use it our own (not shopify) website.

We want to use a photo instead of 'Buy Button'.

We want customers to click on the photo as a buy button and that takes them to cart.

How can we do it? How can we modify 'buy button' code?

Thanks

[Wineaoeasy]

Dear Sir,
How can I see the file?
Regards
Winesoeasy