You uninstall Abel, deleting it from your hard disk, in the same way as you'd delete any other package installed on your PC. This varies slightly according to the version of Windows you're using. You start by going to the Windows Control Panel; you can do this by clicking on the Start menu button (usually found in the bottom left-hand corner of your screen), then selecting Control Panel or Settings/Control Panel.
When Control Panel appears, for older versions of Windows, select (double click) "Add/Remove Programs"; for newer Windows versions, select "Programs and Features". In both cases, a list of the programs installed on your PC will appear.
Now select Abel from the list, and click "Change/Remove" or "Uninstall/Change"; you will be asked to confirm that you want to uninstall Abel, and if you do so Abel will be uninstalled.
This removal process will only delete files that were copied to your computer when you originally installed Abel. It will NOT delete any method collection files you have created or special configurations you may have set up. You will need to delete these yourself by using the Windows Explorer (for example). These files will typically be stored in the Abel directory, which is usually C:\Program Files\Abel 3.
If you are using a PC with Windows 95 or an early version of Windows 98, when you installed Abel you may also have had to install Microsoft DirectX (it is included by Microsoft in all later versions of Windows, and you will not then have installed it yourself). The Abel uninstall program will not remove DirectX from your system, and there is normally no need for you to do so. Removal of DirectX should only be undertaken by an expert who thoroughly understands the consequences and is familiar with deleting registry entries by hand.