You'll need to make code customizations with 2 files. The first one is your product-grid-item.liquid file. You'll need to replace a section of code with new code. Check which version of Pipeline you're using to help find the correct code required. Click on the link below to open your product-grid-item file in the HTML/CSS editor, find the old code based on your version, highlighted in a red box. Then replace that section with code from the green box of your version. The second step is to add some style code to the very bottom of your style.css.liquid file.