Using a secondary monitor as a primary monitor on MBP with lid closed

This was tested on a MBP but probably will work on the other models.

First, download InsomniaX. On installation there will be a checkbox that says "Anonymous Reports" or something along those lines; uncheck it if you don't want the people who created InsomniaX to get reports on your system.

Next, start InsomniaX. An item will appear at the top right with the rest of the menu extras. CAUTION: DON'T click Enable Hibernation because this can cause serious problems and even break your computer if you have "Secure Virtual Memory" checked off in the security settings in System Preferences. Just click Enable Insomnia.

Your menu extras should look like the following. InsomniaX is the blue one. Processor is the one with the square and a number at the bottom right. Displays is the one that looks like a display. It doesn't matter what order they come in.

Then, download Fan Control. This will show up in System Preferences. Click on that and set the "Base Speed" slider all the way to the right so that it says 3500 RPM.

After, go to Finder and click Command + Shift + G and type in "/System/Library/CoreServices/Menu Extras". Select and Double-Click the item named Displays.menu and the item named CPU.menu.

Connect your external keyboard, mouse and monitor. Then click the Displays menu which popped up at the top right and click Turn on Mirror Displays. The next part reduces what could become a SERIOUS problem (overheating). It will reduce performance but the overheating could destroy your screen and/or the entire computer. Go to the CPU menu and click "Single CPU". Now turn the brightness all the way down on the MBP so that the screen goes black. Next, turn keyboard illumination down all the way so it is not lit up at all.

Close the display on the MBP and begin.

To go back to normal settings open the MBP and turn the display back on. Go to the CPU menu at the top right and set it back to "Dual CPU." Hold down command and click the CPU menu item and drag it off. Hold down command and drag off the Displays Menu. In the InsomniaX menu click Disable Insomnia and then click quit at the bottom of that menu. After, go to System Preferences --> Fan Control. Lower the "Base Speed" slider to 2300 RPM.

NOTE: I will be making a program that will quickly do this entire set up for you. I will include the download link when it is finished.