Deleting a Service Application with Power Shell

Hi,

Here is how to delete a service app with Power Shell

Run

$spapp = Get-SPServiceApplication -Name "<Service application display name>"

Then to keep the data

Remove-SPServiceApplication $spapp
Or remove Data
Remove-SPServiceApplication $spapp -RemoveData

More details

http://technet.microsoft.com/en-us/library/ee806875(v=office.14).aspx

If the above does not work you can try this command(Dirty Method):

stsadm -o deleteconfiguratio nobject -id <ID>

Where you can change "<id>" to $spapp (Suppose to, did not test it) 

you can also run get-SPServiceApplication for a list.