Change to root directory

Firstly, my wordpress skills is really basic and I have tried searching but could not get a definite answer.

Here’s the situation, currently website is mydomain.com/wp. So everything is based on wp folder. Like images (mydomain.com/images). Now I want to make to put all the wordpress into my root folder (mydomain.com). There are many pages, posts, media etc.

So I need all the links, content, data, images, buttons, all to aligned with this change. Including posts where currently, there is some content containing links to full address like mydomain.com/wp/contact.html.

So how to handle that? Do I need a new database? Do I need to install wordpress on root folder? And which kind of format is better for internal links (mydomain/xyz.jpg or simply /xyz.jpg)