Please be more specific about what exactly you don't understand.
I think that there are enough tutorials a guides about Chipmixer around the internet and every person with above average IQ can understand how Chipmixer works.
Why would you even want to use a Bitcoin mixer/tumbler service? Are you trying to "cleanup" some "dirty" Bitcoins? Do you want to buy something on the darkweb?
Beware of the scam mixing services and misleading Chipmixer phishing links. I know that Chipmixer is one of the very few legit Bitcoin mixers, but I've heard some horror stories about people being scammed by them. I don't know if those stories were true and I don't know whether or not those people were scammed by a Chipmixer imposter or the actual Chipmixer website. Be careful.