You would already know the answer to the 'install' question (hint, hint) if you had checked the FAQ Locator. The tachometer display will be wrong until you reset the AFC for a 2 cylinder engine. DSMs only have 2 coils for the four cylinders. People who try to install shift lights have the same difficulty.
Those experiencing other problems should look up the on-line documentation on the A'PEXi USA website and the wiring diagramsprovided by the Super-AFC-DSM users group.
AFC owners should check out the Super-AFC-DSM mailing list on Yahoo! Groups. You need a Yahoo! ID since membership is now restricted. To join, click here.