SharePoint 2013 - Modify Master Page

To get sharepoint master page to look
From:

To:

You can download the master page here, or you can follow the steps below:

here are the steps involved:

Step 1:
In the master page, set the style sheet with the following css style below:

 /* Aligns the Top Bars */
 .ms-cui-ribbonTopBars, #s4-titlerow,#contentBox {width: 960px !important;margin-left:auto !important;margin-right:auto !important;}  /* Turns off the border on the bottom of the tabs */
 .ms-cui-ribbonTopBars > div {border-bottom:1px solid transparent !important;}

And sharepoint site should look like:

Step 2:
Then add the following css:

.ms-core-sideNavBox-removeLeftMargin{ display:none; }

And sharepoint site should look like:

Step 3:
Then we need to cut the following tag and the elements within the tags, and move them above the dashboard tag which is <SharePoint:DeveloperDashboard runat="server" />:
<wssuc:Welcome> tag
<span class="ms-siteactions-root" id="siteactiontd"> tag
<span id="ms-help"> tag

And sharepoint site should look like: