In Studio click on the Map Source 
icon for the Map Source whose .map file you wish to edit and select the Map Editor tab.
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This is the actual code editing pane and shows the code for the map file. Any errors are underlined by a red squiggle whereas warnings are underlined with a blue squiggle. Any changes that you make can be seen immediately using the Map Viewer but will update the live configuration file until you click Save.
Editing Values
If you right-click on a known node that has a value, then a pop-up dialog will appear which will allow you to edit it’s values. You can also change them by either typing directly over them in the editor, selecting from a list of valid entries or if for instance, you select to edit a color entry the colour pallet will be displayed.
Finding Values
If you wish to find a specific word in the .map file you may use Ctrl F to display a Find & Replace dialog.
Using the Toolbar
There is a Toolbar at the top of the Editing pane for common functions:
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This is underneath the Editor pane and has three tabs. If you double click on an entry the Editor pane will move directly to that line and highlight it.
Layers
Selecting this tab will display the list of Layers in your selected map file. The tab will also display a total count of the number of layers.
Errors
Selecting this tab will display the list of Errors in your map file together with the relevant line number in the Map Editor for you to fix the error. The tab will also display a total count of the number of errors.
Warnings
Selecting this tab will display the list of Warnings in your map file together with the relevant line number in the Map Editor. The tab will also display a total count of the number of warnings.
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