Are you still seeing the service offering instances (SOIs) when you open the My Cloud Services Console? If so you can simply decommission them and CLM will mark the SOI and all child VMs as deleted even though the VMs do not exist in vCenter. Otherwise, yes, as James pointed out, you can mark the VMs on BMC_ComputerSystem as deleted however I would only do this if the first method doesn't work.
I tried doing operations such as stop, start and decommission to the service instances on CLM, but I got an error (as below) since the VMs weren't available on VCenter.
I raised the issue to BMC Support and they provided me the following steps to remove the SOIs from My Cloud Services Console:
1) Delete the entries fromBMC.CORE:BMC_Serviceofferinginstance. Please perform this on both EAR and CAR.
2) Delete the entries from BMC.CORE:BMC_ComputerSystem.Please perform this on both EAR and CAR.
3) Decommission the VMs from BBSA. This will mark thoseVMs in the BBSA database as deleted.
Many thanks for your comments.
Can you try a decommission and show us the error you get? Often you will get an error however CLM will go ahead and "decommission" it from the CDB, marking all of the related CIs as deleted. I am not disagreeing with support's guidance here but in the past when I have ran into this issue it always works.