How to uninstall a program?

I need to uninstall a program. How can I do it?

Contact the developer to find out if they wrote an uninstaller, or if the program is entirely self contained.   Preferences may be left behind in the Go menu -> Go to Folder and selecting ~/Library folder.

Some may also be found in the Library folder under Macintosh HD and System.    Generally speaking, unless you are certain these files belong to the program it is unwise to remove them.    Some may be stuck in your Documents folder such as Microsoft Office and Appleworks that store recently opened document shortcuts there.

There is only one program that is able to completely remove applications without being installed first:

https://www.ccleaner.com/ccleaner/download?mac

It also removes system caches, which should only be done on a system that is backed up.  Use it just for application removal.

Other programs that need to be installed first before installing the application to be removed are:

http://www.appzapper.com/

http://www.easemac.com/products/maccleaning-free.htm
http://www.reggieashworth.com/appdelete

http://appcleaner.en.softonic.com/mac

Smith Micro's Spring Cleaning

Note many of these maintenance tools can be more damage than good if they are run at the wrong time, or the data integrity on the machine is not great.  Always backup your data before using such tools.  Also, without a backup, if you remove a program, you may not be able to get it back.  Sometimes if a program uses shared resources and it removes a shared resource, it may disable another program.  A clone backup before any install with either Carbon Copy Cloner or Superduper will allow you to recover the system to the state just before the install. Make sure your clone is bootable and exactly the same size as the original.  If it isn't your cloning software may be engaging in archiving instead of cloning.

Most software you can just delete and it will be gone.  Some install fonts, and other preferences that might cause problems for different versions if installed later.   Others include an uninstaller in the software disc to be used if you need to remove them.   Several highly rates Mac anti-virus and Malware programs include:

http://www.avast.com/

http://www.malwarebytes.com/

https://www.clamxav.com/

Mac Antivirus Download: Advanced Malware Removal | Sophos Home for Mac

And they should only be installed one at a time, and not concurrently.   Personally I have found the first two most effective.    Other optimization tools should not be installed without consulting on the board first.  Two really good index free file search programs that help in locating files independent of Spotlight include:

Easyfind from Freeware applications and services for Mac - DEVONtechnologies

http://apps.tempel.org/FindAnyFile/index.php

If you are uncertain if anyone attempted to install cleaning software on your Mac before, or if you believe you have been hacked after running the above anti-virus tools, these tools can help you find cleaner type programs that should not belong.