Question about apache site

I dont know if this is in the right topic.

I have bought a premade website which i need to host on a vps. I have succesfully done that. But the person who sold me the files just changed something and i cant login on it.
Does anyone know if there is a way to edit something in the html skelleton which can remove this problem? And remove his right to cut me out, i can send the files to show.

thxx

Can't login to what?

Is it wordpress based website or something else.

What CMS are u using? is it Wordpress or something ?

If you can't log in on it probably something about configuration no? Does your website have database? Try to check it and change the password there, If not password problem then show us the login script or the way you do it.