Comment out  this code block:

 

<SharePoint:UIVersionedContent ID="WebPartPageHideQLStyles" UIVersion="4" runat="server">
<ContentTemplate>
<style type="text/css">
body #s4-leftpanel { display:none;
} .s4-ca {
margin-left:0px;
} </style>
</ContentTemplate>
</SharePoint:UIVersionedContent> 
 
Further down you will find three lines which prevents the left column for rendering

Comment out  this code block:

 
<asp:Content ContentPlaceHolderId="PlaceHolderPageImage" runat="server">
</asp:Content>
<asp:Content ContentPlaceHolderId="PlaceHolderNavSpacer" runat="server"></asp:Content> <asp:Content ContentPlaceHolderId="PlaceHolderLeftNavBar"runat="server"></asp:Content>