Make sure you accurately diagnose it first. A lot of people jump to the conclusion that the headgaskets are bad when in fact there is a different problem entirely. And remember, if cylinders 3,5,4, or 6 are getting coolant into them you are looking at a bad block. There are no coolant passages near those cylinders to leak coolant into them from a bad headgasket.
For what it's worth the "In Search of the Experience" video is okay but could be better. I am a little more detail oriented than those guys and use a few other tricks to ensure a good repair.
My number one favorite "trick" to do on these is remove the rubber motor mounts. Dropping the engine down another 4" without the mounts in provides a lot more room to work around the back of the engine. It is more beneficial on D2's but it really helps provide better access to the back headbolts on the drivers side! Whatever you do, don't round the bolt heads off.
Also, the parts "kit" that you can buy from Atlantic British isn't really the best. If you see the parts side by side Genuine parts are much higher quality. There are a lot of extra parts that come in that kit that you don't really need, like injector o-rings.
