There are a few things you can do to reverse layer order in Photoshop. The first is to use the command “layer-by-layer” to change the order of the layers. This will cause the layers to be put in a new order, with the bottom layer on top. The second is to use “undo” and “redo” commands to change the order of the layers. The third is to use “select all” and “drag and drop” commands to select all of the layers in a document and then drag them into a new document. Finally, you can use “paste” and “cut” commands to copy and paste the layers into another document.