Hello @stevebarr32,
Thank you for reaching out to the Community and telling us about this issue. I'm sorry to hear you're running into this problem. Normally, at the new year, Quicken automatically generates a 2024 budget based off of your 2023 numbers.
If it didn't do that or if the numbers are incorrect, then you would need to edit it; there isn't any way to delete just one year from an existing budget. If the budget is mostly the same from month to month, you could manually update one month, then click on the column header and choose the appropriate copy option to copy that to all of the other months for that FY or CY.
I hope that helps!