webdesign security

Hi guys,

i have a small movie streaming website and would like to change the whole design of the website to make it unique, so a decided to hire a freelancer and pay him for the job. I would like to know how does this process work? I mean is that not too risky to give him the login details from my website to make the changes? Can someone give me an advice who has already done this on his website.

Thanks in advance (and sorry if this is in wrong section)