I always both dread and look forward to it. The little tweaks are pretty easy and I love seeing how they tighten up my work and make me look good. That is, if not too many things change. If that happens - then I have to get my nose to the ground and track down the entire plot line to make sure things aren't repeated or lost or dropped.
The other kind of editing is the big stuff. The kind where whole parts or large themes need to change. Where the last half of the novel just isn't right or a whole character (or two) need to be eliminated. Then it's time to reach for both the antacids and the Tylenol.
The trouble with these big edits is that there isn't a map to follow. Sure the editor, if that's whose guiding these edits, may give you some idea of how to proceed. But more than likely, they won't. It will all be up to you to dismantle the novel, rip out parts, remake them, and try to fit the whole thing back together again into a smoothly working machine. Unfortunately at this point things can get irrevocably destroyed - purely because so much is going on.
I always look at writing a novel like weaving. There are a bunch of threads representing plot lines, characters, antagonists, hints, trails, red herrings, etc. And each one has to weave between all the other threads. In the end they have to look like a tapestry with no knots, holes, or threads - which start out but don't go anywhere. And it's hard. Especially when you've finished and the picture looks good until you get a really good look at it and see the flaws (or someone else points them out to you). Undoing the whole thing sets up the chance for tangles and knots. Or worse, a whole thread disappearing. And that's not even taking into account all the new threads coming in.
So I hit the paper. Plot and map. Hope things are going to become clear by the end while I spread each thread carefully out and weave them back in properly. By the end of the process, things generally look good. The panic goes away. The tears dry up. And the novel, that was such a mess just a month ago, looks like a novel again.
I always say, you can't fix what isn't there. First drafts, however abominable, have to hit the page before the real work can begin. But that doesn't mean editing is the easy part. It's not. It's just as hard as the first draft. In fact, I don't really think there are any easy parts to writing.
So what does that make me? I struggle with my writing but I still love it. I get an adrenalin rush every time I figure out an issue, solve a puzzle, or figure out how to really put one over on my reader. I get a buzz when the novel is put back together and all the parts snap into place and start to hum perfectly. When the picture is complete and it's smooth and masterful. For me, writing is like an extreme sport - luckily with only mental danger. I'm not that coordinated.
Yeah . . . Editing, ug! But I love it. I really, really do.