[header] How to write a codicil [title] Read your original will. [step] Make sure that the copy that you have is the final version of your last will and testament. Also gather any other existing codicils to your will. 
Then, identify the problems existing in the will and make note of them. [substeps] Common reasons why people decide to make an amendment to a will include: executor of the will has passed or is no longer desirable.