Building a site to replace my current website that is up and running..

Hello.

I need a little bit of help. I am building a new wordpress site that will replace my current website and use the same url. I’ve been told that you should not change the entries under general setting where I set the site url once I have begun development of the website. I did in fact test this and it broke all the links to the media I had inserted into the website.

So i’d like to set that site url the same as what it’s going to be when I go live. However once I do that(set the url to what it’s going to be when I go live) I lose the ability to manage the site from the webserver that wordpress is installed on as it wants to resolve to my site that is up when I enter the url on the wordpress server. I also lose the ability to connect via localhost. Can someone help me get around this or give me the proper procedure?