Yes. Open the notebook and rewrite its instructions yourself whenever you want. You do not need a new notebook, and everything else stays as it is. Save the old instructions as a Page first, so you can go back if needed.
More in Notebooks, Agents and Automation
Can I add Website links to a Copilot notebook?
Yes, notebook references now accept links to websites as well as files. That is useful for anything online that changes, such as academic or legal material, because the notebook works from the current published version rather than an old download.
Can a Copilot notebook reference a Recurring meeting?
No, a reference points at one specific past meeting, even in a recurring series. The workaround is to write in the notebook's custom instructions that it should summarise that meeting since last time. Then you just open the notebook and ask it to run.
How do I share a Copilot notebook or Agent?
Both share in one click. A notebook has a share button at the top, and an agent shares from its three dots menu. You can only share with people inside your own organisation, not with anyone outside it.