Hi!
You can get IE 11 by running Windows Update for example.
Depending on your environment, you might need to approve the update in WSUS for the clients to be able to install it. You can also create a package that can be installed on the clients, either by running it manually or deploying to them with SCCM for example.
To see how to create the package, take a look at my post here:
http://guidestomicrosoft.com/2015/04/15/deploy-ie-11-using-sccm-2012/
The first part is how to create the package, the second will show you how to deploy it with SCCM, something you can skip if you do not have it in your environment.