body: Lets say there are 3 entities: `X ,Y ,Z`
  
  
  * `X` owes money to `Y` stipulated in a contract named `C`
  * `Y` wants to change the contract , so that `X` now owes money to `Z` - we will call this contract `C1`
  
  
  What needs to happen for the creation of `C1`?
  
  
  * -Does `C` need to be terminated ?
  * -Is `C` attached from now on as an annex to `C1` ?
  * There is no need for `C1` , we just update in `C` the side that is owed money (`Y->Z`)
  
  
  I do not understand how the update of a contract happens if you want to update just one side , in our case the one that is owed money - from `Y` to `Z`
    
    
  
  **Update**  
    
  
  Thank you all for your responses.I will give this update to clarify what i want to ask.
  
  
  The question is not rlly about what`X` owes ( the right/value) or what type of contract it is.What i am interested is how can the paperwork be reduced and generalised lets say digitally when the contract `changes hands`.
  
  
  Can I , as a digital service provider , get `Y`'s original contract (as a source of Right/Value) , provide a generalised form for him and `Z` to complete and sign (digitally) as seller and buyer , put them together (initial contract and form) and voila now `Z` legally owns the Right/Value ?
  
  
  I do not want to rewrite the part of the contract that remains constant (the right/source of value)
  
  
  I want to know what is the simplest way to preserve the part of the contract that remains constant - the right/value- while minimizing the paperwork needed when `changing hands`.
  
  
  `X` owes `Y` stipulated in contract `C`  
    
  
  `Y`->`Z1`->`Z2`->`Z3`....`
  
  
  When the contract changes hands from `Z1` to `Z2` to `Z3` etc can i keep the original contract as the source of right/value and just provide a form between the buyer and seller of the right ?
  
  
  I want to reuse the source of value part/paperwork/contract.
  
  
  So if Z has the original contract ( X to Y) and also a contract that says (Y gave to Z) is it enough legally ? Can Y do malicious activity and say : i have the original contract that says X owes me.In this case which contract gets priority ?
  
  
  
title: Updating a contract