Hi Lizzie May
It's pretty easy to do. Simply melt the soap scraps in some water and pour into molds. Here's a short video with a few ideas for add-ins that will help you see exactly what to do. Wishing you the best.
You can put the scraps in a plastic zip-lock baggie (grated or shavings) and add about a teaspoon of unscented Dove body wash. Work the bag in your hands until the mixture is a fluid. Cut a small corner out of the bottom of the bag and squeeze the mixture into your soap molds. then let dry.
not all 'soaps' will emulsify... but it never hurts to try ...
put in a glass container ,put in oven @ 200 until melted .Handle with care when taking out