There was a post on the forums asking about how to remove a session if the max sessions (5) had been reached. You could use Get-Process to find and kill a WsmProvHost but killing things is never a good idea. There is a Get-WSManInstance but it’s not very friendly so I’ve wrapped that and Remove-WSManInstance in to two functions that are much more user-friendly. Just copy and past this in to a file and you can use Import-Modulein your profile to add these functions in to your environment.

<#
.Synopsis
Display WSMan Connection Info
.DESCRIPTION
This is a wrapper to Get-WSManInstance
.EXAMPLE
Get-RemotePSSession ServerABC
.EXAMPLE
$s = Get-RemotePSSession ServerABC
$s | Remove-RemotePSSession
#>
function Get-RemotePSSession
{
[CmdletBinding()]
    Param
    (
        # Computer to query.
        [Parameter(Mandatory=$true,
                   ValueFromPipeline=$true,
                   Position=0)]
        [string]
$ComputerName,

# use SSL
        [switch]
$UseSSL
    )

    Begin
    {
        try{
            Add-Type  @"
namespace JRICH{
public class PSSessionInfo
            {
                public string Owner;
public string ClientIP;
public string SessionTime;
public string IdleTime;
public string ShellID;
public string ConnectionURI;
public bool UseSSL=false;
            }}
"@
        }
        catch{}
        $results = @()

    }
    Process
    {

$port = if($usessl){5986}else{5985}
$URI = "http://$($computername):$port/wsman"
$sessions = Get-WSManInstance -ConnectionURI $URI shell -Enumerate

foreach($session in $sessions)
        {
            $obj = New-Object jrich.pssessioninfo
            $obj.owner = $session.owner
            $obj.clientip = $session.clientIp
$obj.sessiontime = [System.Xml.XmlConvert]::ToTimeSpan($session.shellRunTime).tostring()
$obj.idletime = [System.Xml.XmlConvert]::ToTimeSpan($session.shellInactivity).tostring()
            $obj.shellid = $session.shellid
            $obj.connectionuri = $uri
            $obj.UseSSL = $usessl
            $results += $obj
        }
    }
    End
    {
        $results
    }
}

<#
.Synopsis
Logoff remote WSMAN session
.DESCRIPTION
   This function will take a JRICH.PSSessionInfo object and disconnect it
.EXAMPLE
$s = Get-RemotePSSession ServerABC
$s | Remove-RemotePSSession
#>
function Remove-RemotePSSession
{
[CmdletBinding()]
    Param
    (
        # Session to be removed.
        [Parameter(Mandatory=$true,
                   ValueFromPipeline=$true,
                   Position=0)]
        [jrich.pssessioninfo[]]
        $Session

    )

    Process
    {
foreach($connection in $session)
        {
Remove-WSManInstance -ConnectionURI $connection.connectionuri shell @{ShellID=$connection.shellid}
        }
    }

}

Edit: Thanks Alex for catching the use of “CredSSP” vs “UseSSL” which is the common arg on PSSession cmdlets!