how can i integrate wordpress with dreamweaver?

It all depends on what you mean by integrating WP into DW?

As recommended by @Nancy OShea , of course you shouldn't modify the core CMS files, but if you want to develop your own Theme, or adapt an existing theme through a child Theme, or set up an extension, DW lends itself well to the game.

All you need to do is work with a local server, to activate PHP support and manage the database, and type your code into the appropriate files...

You can also use the live view part as a content editor (albeit with certain limitations, but sometimes handy)...

DW also offers a code analyzer that provides a certain degree of flexibility. To activate it, go to Site menu > Site options > Site-specific code tips, and select Worpress in the selector. You'll get a classic tree structure, but then it's up to you to refine the areas to be taken into account.

You can also define an external code editor to handle more complex tasks if required.

You don't.  Apples and alligators can't be integrated as they're two vastly different things.

1. WordPress is an online site building platform that is dynamically driven with PHP/MySQL code.  You must maintain the site through WordPress's online Dashboard.  See Introduction to WordPress. 

2. Dreamweaver is a desktop code editor for creating static HTML, CSS and JavaScript files.  See Dreamweaver User Guide.

Unless you're an expert PHP coder with a working knowledge of WordPress Child Themes, DO NOT attempt to edit WordPress files in a code editor. You'll break the site and make it completely useless.

Hope that helps.