Having escape routes is the primary concern for me. You always want to be able to go back to what you had before, worst case scenario.

I also try and combine other updates to allow minimal downtime on products/services.

Equally some change management, think about what other services might be affected by taking something offline, do you need to notify anyone else?

Finally communicate what you are doing to those that might use your services, keep them informed as to the benefits of your work and when they can expect something to return (and always add some contingency), keeps everyone happy.

Doing work like this is always a good learning experience, I’ve always learnt the most from my mistakes!