1 - 2 horas
Me and the wife were getting ready to watch a DVD when the machine thought it was time to die. This is an original PS3 so I wasn't ready for it to go.
I followed this sites YLOD guide and it went extremly smooth and easy. It took me around 2-3 hours total but that is because I was inspecting everything while cleaning the dust off of an eight year collection. When it can time to fix the motherboard, that was the only time I was nervous. I did take another fixit users suggestion of using the oven first (heat the oven to 250 degrees celsius, shutting off the oven and putting the motherboard inside for 7 minutes). Most people suggested using a heat gun on a setting of 250 degrees celsius. I did have access to a heat gun with two settings. The coldest being over 500 degrees celcius. So I heated the CPU and GPU for 7 seconds or so shorter then suggested. Put it all back together and wasn't expecting it to work, but it started up fine and is working. Oh, I also switched out the power supply with the cooler running model.
Just take your time, separate the screws into muffin tins and follow this guide and everything should work fine. Only time will tell how long this fix will last though. But getting anything extra out of it now is a bonus to me.
iPhone 5 Audio Control and Power Button Cable
iFixit Opening Tool
PlayStation 3 Yellow Light of Death (YLOD) Fix Kit