This is going to be more of a stream of thought than a specific guide. There are a lot of moving parts in this and no one seems to have the whole answer. So, here's what I've been working around so far.
Of course, you must have a tenant set up in Office365. It must have Azure AD Connect, or whatever they're deciding to call it these days, functioning correctly. There's plenty of resources for getting that far, so I won't rehash that.
Many of the commands are run in the Lync PowerShell on the FE.
"Get-CsHostingProvider" should look like this:
Identity : LyncOnline Name : LyncOnline ProxyFqdn : sipfed.online.lync.com VerificationLevel : UseSourceVerification Enabled : True EnabledSharedAddressSpace : True HostsOCSUsers : True IsLocal : False AutodiscoverUrl : https://webdir.online.lync.com/Autodiscover/Autodis coverService.svc/root
The syntax is: Set-CsHostingProvider -Identity "LyncOnline" -VerificationLevel UseSourceVerification -HostsOCSUsers $True -EnabledSharedAddressSpace $True -AutodiscoverUrl https://webdir.online.lync.com/Autodiscover/AutodiscoverService.svc/root
Download the SkypeOnlinePowershell.exe. I'm not going to link to it because Microsoft likes to change locations. Install that on the same Lync FE.
Then, in the Windows Powershell:
Import-Module SkypeOnlineConnector $cred = Get-Credential $CSSession = New-CsOnlineSession -Credential $cred -OverrideAdminDomain "yourcompany.onmicrosoft.com" Import-PSSession $CSSession -AllowClobber Get-Service "msoidsvc" Set-CsTenantFederationConfiguration -SharedSipAddressSpace $true
msoidcli is another download from Microsoft. That and the SkypeOnlinePowershell are plugins to enable functionality. You'll probably need them.
You then need to move a pilot user to the online system. The command is: Move-CsUser -Identity user@sipdomain.com -Target sipfed.online.lync.com -Credential $creds -HostedMigrationOverrideUrl https://adminXX.online.lync.com/HostedMigration/hostedmigrationservice.svc -DomainController dc-internal-name.local
The adminXX url needs to be grabbed from your S4B online admin portal. It's just that part of the url that you see when you're in the S4B dashboard. The identity is the test user you want to migrate. I ran into a lot of trouble getting this to work. I had to figure out the above commands and then I had to wait for the SharedSipAddressSpace to take affect. It was not immediate.
At the moment I'm still not able to route calls properly, but the user is showing up in the online S4B admin interface as being migrated. Lync also shows the user being in LyncOnline. I'll edit this post as I make progress.