I've heard that people have been able to modify their AsRock Z170 mobos to work with an i7 8700k, are there any chances that I can modify my MSI Z170-G45 to do the same?
Nope. There are some professionals that have gotten the systems to boot with a 8700k, but it is not good for daily use and not something the average Joe can do. Just go get a cheap z370 board. You can get one a cheap on for around $100.