This guide takes off at the stage where you have completely removed the LCD panel from the iMac, and disassembled it. The glass pane which actually holds the electronics (the IPS LCD) is very fragile. Be very careful when removing the side brackets from the screen, there are electronic components on two sides of the glass pane! Store the glass pane in a safe place while working on the backlight system.
After removing the glass pane (with hopefully the electronics still attached to it) you'll be left with the assembly just containing the backlight (and backlight cable). Disassemble further by removing the black plastic bezel (one side contains screws) and removing the layers of filters. Be careful with the filters and remember in which order they where stacked!
This leaves you with an empty panel just containing the backlight leds in a strip near the bottom. It really surprised me that these leds where all you need to illuminate the screen. They must be incredibly bright and that might be the cause of this problem.. Show us some pictures!
I'm very happy so far. This fix cost me a couple of hours but that's all! A replacement screen is hard to find and costly, this was practically free. I'd recommend this procedure to anyone experiencing yellow tinge and who is comfortable working on the inside of the iMac.
iMac 2010 LCD screen repairability : 9/10