As requested, people willing to learn how to hack whatsapp very badly. Most reason is because cheated by his or her spouse.
Okey lets begin. I am writing this in english although english is not my daily language.
There are several ways to hack or hijack someone whatsapp account. Stealing activation code sms sent by whatsapp before used, perhaps she saved this sms.
I am not sure that will work.
Or you can try another way that I tried, nad its work perfectly.
Before you begin, you still need your girl’s cellphone ( i will say this is an A number), then you will need another cellphone ( B number) to receive the messages sent to A number. Please note, there shouldn’t be whatsapp installed and configured in B cellphone i recommend you use android system as I do.
Once again, you should do this with A cellphone in your hand, and the owner is not know about it.
Now start install whatsapp in B cellphone, in the middle of the installation step, you will be ask to insert cellphone number, there you need to insert the A number. Then whatsapp server will send a code in short message to validate the account.
The sms should be sent immediately, then check into A cellphone. If you recieved the code, insert it into the next step of Whatsapp installation process in B cellphone. Your whatsapp should get verified. Don’t forget to deleted the sms sent by whatsapp and clean it up from trash folder.
Test it and let me know if it works for you, it is working for me.