How to change layer size in photoshop
You're in a situation where you want to change the layer size only and not the canvas size or image size.
Click on the layer and shortcut CTRL+T, you can also go to the menu and click Edit and then Free Transform or just Transform depending on what you need to do.
Another tip is while in Transform Mode you see the actual px size of the layer for both width and height below the menu. If you know how much larger you want the layer just change the pixel size on-the-fly
Watch out so the layer is not linked with other layers, in that case just highlight the linked layers and chose "unlink layers". If you do want to include other layers but not all, just highlight the layers you want linked and chose "link layers".
I did this in a project today and worked great, hope someone else will find this useful.
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