As an example, Land by Type theme will be used. The use case could be that the users found it difficult to distinguish between Indication, SHA and CHA, therefore they wanted to have different colors for each of them.
<ol><li>This is how the [[Map Display window Window]] inside IMSMA looks like before any changes on the .mxd file:
[[Image:Existing_symbol0.png|300px|center]]
<div align="center">
'' Map Display - Before changes''
</div></li><li>Open IMSMA.mxd with ArcMap and go to Land by Type layer. Double-click on the symbol that you would like to change (SHA).
[[Image:Existing_symbol1.png|250px|center]]
<div align="center">
'' IMSMA layer Land - by Type''
</div><ol><li>Double-click on the symbol that you would like to change (SHA).</li>
<li>The following window displays.</li>
[[Image:Existing_symbol2.png|350px|center]]