Hello, Im really sorry for the excess burned ink that left on pages and the front cover too! because of due to microwaving longer was the cause of it, hopefully that wont happen in a near future for doing this again and pretty much learned my lesson. :p
In the future, I recommend using a clothes iron instead of the microwave. You have way more control with a clothes iron, plus you can actually see what you're doing.
I recommend a hair drier for taking manga apart... While warming the spine, gently pull at the page. If the glue is warm enough, the page will separate from the spine without rips or other defects.