Downgrade TPM chip from 2.0 (7.63) to 1.2 (6.43)

I need to downgrade a TPM chip from 2.0 (7.63) to 1.2 (6.43); the current Softpack SP81900 only has the 7.62 to 6.43.

Does anyone have the 2.0 (7.63) to 1.2 (6.43) file to use with the utility?

Without this, I don't seem to be able to enable BitLocker.