How to migrate the images in Prismic from my old repository to the new repository?

Hi, we are migrating content from one repository to another. We are utilizing the export/import feature in Prismic to migrate ~1500 Documents. Looking at the exported data, each document is a JSON file with references to the images. How can I migrate the images in Prismic from my old repository to the new repository?
Additionally, we are migrating from a Legacy repository to a Slice Machine repository. Are there any tips or documentation for how to convert the legacy slices into a format compatible with Slice Machine slices? We had a call with Prismic support last year and it sounded like this is something other customers have done using scripts.

Hello @kamyar.dabiriasgari,

Welcome to Prismic community, and thanks for reaching out to us!

Unfortunately, Our Import-Export tool doesn't export the Media Library images. It does only export those Images available in Published documents.
You can save individual images from Prismic's media library to your local system.
Go to Media Library -> click on any image -> again double click on image -> right-click and find the save image as option. Then, to bulk upload images in the Media Library UI in your new repo, select all your images and drag and drop them into the Media Library. I understand that the suggestion may seem a bit manual.

There is no official guide for migrating from the Legacy Builder to Slice Machine. This can make the process difficult as there may be confusing and breaking changes we cannot avoid now.

As a result, we recommend that users either continue using the Legacy Builder for older websites and select Slice Machine for newer projects or attempt to manually create an identical copy of the older repository if they wish to use it for more senior projects. We understand that this process can be pretty time-consuming and not ideal, but it's the best option for avoiding content loss.