How to remove Inactive DEM-O

Hello while i was performing distributed deployment for VRA, i got some error in DEM-O and had to re-install it .

I was able to successfully remove the binaries from the DEM server but vRA Portal under 'Distributed Execution Manager' still show the faulty DEM with status = offline

Is there any why or SQL query to clean that from the VRA portal?

thanks,

MG