In Management Studio, you can connect to Integration Services.

(choose Connect and then click Integration Services...)

There you will see two folders:

Running packages and Stored packages. We will look at the last one, which has also 2 folders:

File System and MSDB. The first one is well... for packages stored in the file system 🙂

The second one is for packages stored on SQL Server itself.

You can view and run packages from there.

When you have BIDS, you can also create a package that runs other packages (a so called master package). There you need the Execute Package Task.

A final option is to go to the fysical location where you've stored the package with explorer and then double-click the package. This will launch the tool dtexecui that will execute your package.

(actually, you can also launch packages from the command line, but that would take us too far)