When I tried to remove the servers from DAG to recreate it I recieved an error because the cluster couldn't find the quorum. I decided to try a not good way to solve the problem, but using the following steps I could have the DAG working fine.
1- Removed every server from DAG using Remove-DatabaseAvailabilityGroupServer -Identity
2- Cleaned the cluster using this command to every DAG member cluster node
Done, now you can delete the DAG and recreate it.