And, finally, additional tool which was super awesome: FLASHLIGHT. Small, flashlight is awesome when just examining the internals prior to removal/especially if you have a way to prop up the LCD panel, since it will cover the main board, and you need some idea as to where what is.
Another comment on DATA & LCD Temp. Sensor cables: I had to remove the vertical sync, and the backlight cable, however, if you have an assistant or/can carefully rotate the screen clockwise/and then have it held up about 5" to 6" at a slight angle, you do not need to remove LCD data cable or LCD thermal cable, however - IMPORTANT: you must have a second pair of hands/or way to securely prop up the LCD. Also, don't rotate too much, since then you will pull out LCD data cable, and it renders the whole exercise moot, or can damage the cable or connector.
Want to add a comment on this w/reference to HDD & thermal sensor. HDD used: WD1002FAEX - 1TB WD Black. Temperature sensor on this model iMac has a little tab/plastic protrusion, Apple HDD actually has specific opening for it. With this HDD/any after market WD HDD you should use small electrical wire cutters, and just cut off the offending piece of plastic from the iMac sensor. Insert it as specified, closest to SATA/PCB board, take a picture first before taking it out, and it works like a champ!