To change the bower’s component installation directory as you want you first need to create a .bowerrc file and define the custom location in this .bowerrc like the below.

{
    "directory": "yourCustomDirectoryLocation"
}

Then as usual just make a bower.json file where you will write down all the dependencies for your projects like the below.

{
  "name": "YourProjectName",
  "description": "Description of your project",
  "homepage": "http://yourProjectUrl.com/",
  "author": "Yourname <your@email.com>",
  "dependencies": {
      "bootstrap":">= 3.0.0",
      "jquery": "~2.0.3"
  }
}

now run bower install command and all the required dependencies will be installed to your defined directory (as you configured in your .bowerrc file).