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Simple.

Open up you applications folder and find the app or the folder that contains the app you want to get rid of.

Then just drag it to the trash.

Or, get an application like appzapper, which will delete apps for you.
 
There is a free app called appcleaner which will also uninstall apps on your mac (appzapper isn't free). If you manually uninstall the app you'll have to search for associated files too or they'll stay on your mac (appcleaner/appzapper will remove these too)
 
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