TPM, like most certificate repositories, does not seem to support the delete operation.
I base this observation on the Microsoft article
describing itself as:
This reference provides cmdlet descriptions and syntax for all TPM cmdlets.
The list does not include any PowerShell cmdlet for deleting certificates.
You could try to create a revocation certificate and import it into the TPM,
which might nullify the existing certificate.
If it works, this will not delete it, just add a revocation record
(that is if TPM works like any other certificate repository).
The only option I could find to delete anything is by clearing totally the TPM.
As you are using BitLocker, see the post
Will clearing the TPM make BitLocker encrypted data unavailable?
Quoting from the post:
If you clear the TPM, the encrypted drive will only be accessible
using the recovery key.
So in your case it should be ok to clear the TPM chip. Afterwards,
reboot and enter the recovery key. Once inside Windows, you can
re-enable the TPM chip and set a new PIN.
I would suggest, just in case, to backup the BitLocked disk
(and perhaps even disabling BitLocker) before such operations.