Switching overlay

Is there any way to switch the overlays once placed in the project editor? For example, my students are doing some greenscreen video, and have decided that they now want a tank image to be on top (such as in a voiceover) rather than be behind them. Right now, we are deleting the clips and putting them back in in the correct order (background clip first, then the top layer second). Does not seem as easy as it could be.

Is there anyway to switch the position of the clips in the project window?

Thanks in advance,