@Override
	public void removeOperandReference(int opIndex, Address refAddr) {
		if (refMgr == null)
			throw new UnsupportedOperationException();
		Reference ref = refMgr.getReference(address, refAddr, opIndex);
		if (ref != null) {
			refMgr.delete(ref);
		}
	}
Remove a user defined reference to the operand at opIndex.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/app/util/PseudoCodeUnit.java