Prior to beginning, you'll need the new .pfx file and password for the renewed SSL certificate. You can find more details about exporting to .pfx here.
Before anything, you have to make sure you have all the servers in the deployment on the broker. Head to the top right and select "Manage" then "Add Servers"
In the add servers dialogue, no need to type anything just click "Find Now" and it will load all the servers in the domain.
Select any in the list, then press CTRL+A (MACs would be Command+A) to select them all then hit the arrow in the middle of the two boxes and choose OK.
Server manager will take a bit to load all the information and refresh. Once completed head to "Remote Desktop Services" on the left side.
Then go to "Collections"
And then on the far right, you'll hit "Tasks" then "Edit Deployment settings"
Now select Certificates on the left to get to the "Manage Certificates" Section.
Here we have the 4 services that work off the SSL certificate. You'll have to do the following steps for EACH of the 4 services to update them.
Select any of the 4, then choose "select existing certificate..."
You'll use the second section "Choose a different certificate"
Browse to the certificate and then enter the password. Make sure to check off the last option and hit OK.
You'll be back at the Deployment Options screen, hit Apply at the bottom right, let it load and repeat for the new 3 services. Once done Hit apply one last time and then OK.