I did a long AOD in ... 1999. It was analog, not DVD, so the quality is crap compared to what's out now, but I learned what had to be done.
These are my notes to myself. Enjoy!
Anchor Bay releases it in the US, in shitty picture quality. Ignore that version. There's a version from ... Korea or Hong Kong ... which is by MGM. The picture quality is aces, and it's the director's cut. Get THAT version.
Most of the movie goes unchanged. You gotta do what I did with the Classic Editions and rip the M2V files from the disc and use THOSE in your DVD making program for 90% of the movie, not anything that's been touched and reencoded by your editing program. You'll sneak your own version in when needed and match the frame.
You need the version that aired on the sci-fi channel. It contains two of the deleted scenes in better quality than on the Anchor Bay release. A good version of the extra opening scene where Ash fights Arthur, and a good (and shorter) version of a scene where Ash is lured outside of the windmill (an attempt at building suspense).
The deleted scenes you need from the Anchor Bay release are Ash inviting Henry the Red, and the alternate opening. These are in shitty quality, and need to be color corrected to make them useable at all. You also need to cut out the splice marks on every shot, as these are from workprint.
You are not using the entire alternate opening, just a few extra bits from it to extend the beginning. You need Ash saying "it got into my hand and it went bad - so I LOPPED IT OFF AT THE WRIST." A nice different delivery. You can use the picture from the theatrical. You need Ash shouting and summoning as blue light flashes. ("Kallakah" I think he's shouting.) I forget what the other bits are.
You need footage from Evil Dead 2, most notably a closeup shot of Ash screaming in the vortex as electricity surges around him. That extends the opening slightly.
From the theatrical cut you'll be using "Good, bad, I'm the guy with the gun", "maybe I'm a Chinese jetpilot" (audio only, don't need to redo the picture), and the ending. Seamless branching will make it easy enough to include the alternate ending also. Just stick it in its own chapter after the feature - it will already start on the same frame as your own ending, since you're using the MGM DVD. Create a "story" that rearranges the order and you're all good.