Here is a youtube video including everything you need to put beats back together. https://youtu.be/sKM2dy0uCHU or if you cant fix them he fixes them for $40.
Here is a good link with ways to boot up when wont start i had the same problem not to long ago and used this website to resolve my issue. https://www.macworld.co.uk/how-to/mac/how-to-fix-mac-wont-turn-on-3423817/