To write a simple contract, title it clearly, identify all parties and specify terms (services or payments). Include an offer, acceptance, consideration, and intent. Add a signature and date for enforceability. Written contracts reduce disputes and offer better legal security than verbal ones.
An instalment sale agreement between you and a credit provider allows you to buy a vehicle or asset using the principal debt, which you repay by means of regular instalments over an agreed period, with fees and interest.
The assignor must agree to assign their rights and duties under the contract to the assignee. The assignee must agree to accept, or "assume," those contractual rights and duties. The other party to the initial contract must consent to the transfer of rights and obligations to the assignee.