Location of file on Windows Server 2012 c:\program files\Microsoft SQL Server\120\DTS\Binn
I listed the packages with this SQL Query then created a batch file with the commands below
select * from msdb.dbo.sysssispackages
Exporting SSIS Packages to File:
dtutil /SQL ExportPackage /COPY FILE;C:\Packages\ExportPackage.dtsx
Importing SSIS Package to SQL:
dtutil /file C:\Packages\ImportPackage.dtsx /copy sql;ImportPackage
I recommend opening the files in a text editor and making sure the connection strings are not pointing to an old server.
Also before importing the files, create a visual studio project. Import in all the packages. Go to the properties of the project, choose configuration, build and choose the version of sql server you’re using. Rebuild all the DTS packages.
You do have the option of creating a new visual studio project and importing in all the packages and performing an in place upgrade. However some of these were written in an older version and hard to upgrade. I just used the SQL Server versioning in VisualCron, our Job scheduler, and in some cases 32 bit mode.