In the editor, you need to select the element which you want to edit, either by clicking on it, or selecting from the right hand list, and then open the property sheet and change the Layer attribute.
the only other thing I'd suggest is that the last element you add to a page always defaults to become the 'top' layer on the page.
If there is a specific element you need to move forward or backwards, just remove and re-add the particular component that needs to be on top of the other - that usually works for me. Although it can be a bit tedious, it does seem to work more reliably than tinkering with the layer attribute.
The layer suggestion does work. Just look at the layer value for the element you are trying to cover and make sure the element you want on top has a higher value for layer.
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