Removing old Tilemaps

I was working on my first makecode arcade project (I’m giving my kids Meowbits and I wanted there to be something on it from me).

I had to figure out how tile maps worked and somehow ended up with 5 tilemaps. I couldn’t compile the project because it was too big. If I go through and modify each tilemap to 1x1, I can compile the project, but eventually the old tilemaps are restored.

How can I delete the old tilemaps so they don’t keep coming back?