Go to Admin > Meals > Bulk Student Lunches
Select the year group and form the student is in, then click Choose to bring up a list of students.
Tick the box at the end of the student's row, then select a meal choice at the bottom of the table to assign to that student till the end of the school year.
If you wish to delete the meal pattern, select the student(s) you wish this to apply to, then at the base of the table Assign 'Clear All' to remove all meals assigned to the student(s).