How do I access the data in a UProperty inside a class instance?

So, I might be making this too complicated.

In Class A - I have a UPROPERTY FVector Array. On Init, this will be populated with data.

In Class B, I want to access the UPROPERTY of Class A, such that it has a matching UPROPERTY with the same data (so that I can modify it)

void AclassB::SetMyArray(AclassA* AC)
{
	classBarray = AC::GetClass()->GetDefaultObject<classAarray>();
        //classBarray is a UPROPERTY of Class B
}

This is the simple logic I need, but I want help on syntax, how do I do this right?