To start, you need to make the definition of ' administrative interface. To do this, enter "admin" immediately after the address of the selected website. For example, for://address.rf/admin.
In the fields "Name" and "Password" must be entered the name and password of the site you want. These data should provide the system administrator the Internet service provider that provides the hosting site and change the administrator, because of security reasons.
Next you need to study the structure of the admin interface main page: cap, which is at the top of the page tree search catalog, located in the right part of the window and in the left pane of the administration.
To see the data populate the website, select the interface language, then the upper management left find the full website address.
You may need to enter an administrator on the site, located on free hosting, for example, "Yandex. People." To create your web pages "Yandex", on this resource you must have your own account. So, username and password access you can only get directly from a person having this account. Change or get the password can also only the owner of the account, because all the data is tied to his personal email. To get permission from the owner of the site, personally in contact with him, using the "Contacts" section. Explain the extent of their interest and the need for your intervention in the editing of the website. If you can convince him, maybe get a chance to produce, so to say, constructive interference.
There are different programs for hacking sites. And the fact that they can be used by professionals. If such programs are available for download, most likely, it's just potentially dangerous software containing malicious code or a virus.