Not really.
If all the cameras were Hik as well, then the NVR will auto detect and populate the cams into the new NVR, that are plugged into the built-in POE switch.

You will need the login for the cams - if they aren't sure they have that, price will go up XXX. Because you will probably have to go to each camera and do a factory reset.

Then it will just be a matter of configuring the network settings and router they are using.
Remember to always change the admin account to a different password AND "name"! And change the ports used from the defaults!

Bonus points if you then create additional user accounts for the owner and anyone else they want to give 'limited' access to. This only applies if you are going to be the one managing the system from now on, otherwise let them screw with it however they want.