Let's say you have a broken screen on a macbook pro. You could simply buy a replacement screen for under $100 and fix it yourself. However if you have a broken screen and display assembly the options are pretty limited. A replacement assembly and LCD can run you close to $800 if you have an aging mac. In this instruct able I'm going to show how I made my broken laptop into an iMac. When you disconnect the display assembly from the mac and connect via a DVI cable it will use this monitor as the main screen.

I won't show all the steps as once you see the outcome its pretty self explanatory. 

Items used:
- Macbook Pro 17in 2.4ghz Core 2 Duo w/ 4GB Ram - with display assembly removed and power cord.
- Apple Cinema Display 23in (DVI not miniDisplay port) You can use any screen I just happened to have one of these laying around, they can be expensive to get. 
- TwelveSouth Backpack for iMacs/Cinema display (if you don't use an apple screen you may have to build your own solution)
- Trendent usb 802.11n wireless adapter ( the Apple Airport is located in the screen so when you remove it you'll need to get a wifi    adapter that works on mac. I used one I had laying around the house...it would look even better if I bought a slim adapter)
- Apple Bluetooth keyboard and magic mouse