Create your CSR with the New Exchange Certificate Wizard
Access the Exchange Admin Center by opening a browser and browsing to https://localhost/ecp
Login using Domain\user name as the format for the user name and enter your password.
Click the link to Servers in the left column, then Certificates at the top right, then the + symbol.
The "new exchange certificate" wizard will appear in a pop-up window
Choose "Create a request for a certificate from a certification authority"
In the friendly name field, enter a name by which you will remember this certificate in the future.
This name is not an integral part of your certificate request.
You can check the box and enter the root domain name if you will be generating the CSR for a wildcard. Otherwise, just go to the next screen.
Hit Browse to choose which server you want to store the certificate request on.
If you are doing a wildcard cert, you will skip this step. From the list, select the services which you plan on running securely by using Ctrl+Click to highlight the services.
At the next screen, you will be able to review a list of the names which Exchange 2013 suggests you include in your certificate request.
Review those names and add any extra names by using the + button.
Enter a network share path to save the CSR to your computer as a .req file, then Finish.
You should now be able to open the CSR with notepad or wordpad, and you will want to copy the entire body of that file into the online order process.
After you receive your SSL Certificate from Wisekey SA, you can install it.