This video shows how to remove the radio in a Honda Element. The Honda in this video is a 2003 Element DX. The procedure for removing the radio should be similar on all early versions of the Element.
To access the 4 phillips screws that hold in the radio on the Element, you need to remove the radio bezel cover panel. You can remove the radio cover by using a small pick like in the video or use a plastic prybar. It may be wiser to use the plastic prybars, because the pick if not careful may damage the Element’s dash.
If you plan on changing the radio in your element, one of the best things you can do to speed up the install is to use a wiring harness like this, http://amzn.to/1TPhiwE to connect the new radio to the Honda factory wiring harness.