1 Open up the JPEG. 2  Double-click the background layer to make it a regular layer (background layers always have a background color I think). 3  Use the eraser or whatever to remove the parts you don't want in the picture. 4  To remove white, I would probably try to use the Wand or channels or something like that.or transparency you need to. 1  Open up the JPEG. 2  Double-click the background layer to make it a regular layer (background layers always have a background color I think). 3  Use the eraser or whatever to remove the parts you don't want in the picture. 4  Save it in a format which supports transparency (for example PNG).