@hyoretsu
assuming you use photoshop or something remotely similar, the clone stamp tool is a godsend for doing background work
now, here is my suggestion going forward if you want this to take as little time as possible, typeset first, this way you know what needs to be redrawn and what can be left alone/have a white background. most people don't like white boxes, sure, however, if there is a small border for the text, it not only makes it easier to read, its also easier to do. Note the outline on the text second page in the raw, you could probably quite easily have done that or something like it, and it would have covered up a bit of the more pain in the ass redraw bits. granted on that page I may have opted for smaller text at the bottom because there is no way, without a skilled redrawer, to not affect the art.
I should also mention, if you don't know, when you do the editing and until you release it, scale the pages by 200-300%, this helps with drawing as smaller mistakes when you scale back down tend to fade away and look more like they were always there.
other then that, just know what needs to be worked on and what doesn't, it will make your life a lot easier