?Has anyone in here ever had any experience with a collateral swap

In my own experience, the answer is no but my wife did one as a bank loan officer back before we retired. That was for an automobile loan but the action would be pretty much the same. If you are in a position to do this, the best place to start is by speaking to the lender who holds your present loan. They will probably be willing do do this as long as the new collateral is worth as much or more than what you have now.