With advent of SharePoint 2013 there might be a requirement to migrate an existing SharePoint 2010 solution built using VS 2010 to SharePoint 2013 using VS 2012. And there you might want to re-name the WSP that gets generated when you package the solution.
The WSP name for a solution is defined within the Package\Package.package file of the solution as the “name” property inside the <package> element.
e.g.<package xmlns:dm0="http://schemas.microsoft.com/VisualStudio/2008/DslTools/Core" dslVersion="126.96.36.199" Id="d3150724-5644-479c-99f3-fc99af5bfdc6" solutionId="d3150724-5644-479c-99f3-fc99af5bfdc6" resetWebServer="true" sharePointProductVersion="15.0" name="MyWSPName2013" xmlns="http://schemas.microsoft.com/VisualStudio/2008/SharePointTools/PackageModel">
When you try to open the Package.package file in Visual Studio 2012, it does not provide any direct option to edit the name property.
To edit this, right click on the solution name in solution explorer and select “Open Folder in File Explorer”. Out of all the files and folders inside the solution’s explorer view, open the “Package” folder and right click on the Package.package file present inside it. Select a suitable editor to edit the name property of <package> element and save the file. Clean all the references of old WSP file inside the solution and restart Visual Studio to generate the WSP with modified name.