Please explain me how subject to works?

[Bryan Rodas]

I am getting familiar with the "subject to" method. However, there are some parts where I don't understand like What do you do with the equity that the current owner has? Do you have to pay him cash for that equity? If so, how i can get the money if you dont have it at that moment? It will help me a lot if you explain me the process in a detailed manner. Thank you so much!