Access and delete files from branch on windows GitHUB desktop

I have cloned a repo to my local machine and use GitHUB desktop to acess the files, say for example this is called myrep1. Within myrep1 is a branch called myrepoBranch and I want to delete files in this branch.

I can select the branch but locally can't see the files held there and therefore can't delete anything.

How do I delete folders/files of a branch within windows GitHUB desktop?