Make any amendments as needed and save.
If you did access the "Requisitions - Standard" screen to make amendments, you may or may not need to go to your task list, locate the corresponding requisition task, and approve accordingly. This depends entirely on the nature of your changes. For instance, if you change the price of an item, AIMS will not require you to go to your task list and approve the task, because it will automatically send your task to the first line approver, and remove the task from your list.
An example of a change which does require you to go to the task list and approve is the addition of a file / attachment to the requisition.