Can someone explain how to implement a 51% attack?

Question

Cryptocurrency

Here is a sea of ​​​​videos and rumors about what a 51% attack on the Proof of work cryptocurrency is. But there is nothing clear, this is the generation of a chain of blocks longer than the previous one, and then this chain becomes the main one. The goal is to change the chain to your liking right? Do you know of any material on this subject?

Answer 1

https://vas3k.ru/blog/blockchain/
read to the end
and here if the boys have already fussed