Ok, then it shouldn't be a problem. Once you get the wireless router working and set up open a finder window. On the left side panel there should be an option that says Network. Once you click on it you'll see a list of the other computers on your network. Select your other Mac and press the connect button.
If you sign in as guest than you'll only be able to access the user's Public folder of the other Mac. If you have the user name and password for the other Mac then you can sign in as Registered User and have access to all the files.
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