Release management should be simple when you are working in an Agile way.

You establish the MVP for the release and ensure that you can achieve MVP with the release by only committing to what can easily be achieved in the given release window, based on measuring velocity, good sizing of the work and you leave room for nice to have features which may or may not be a part of the release depending on how the MVP goes.

You make sure that you have the skills and people on the team who can ensure that the release is documented, with training/help material available for the users, even if they are only on the team for the time needed to do this, they should be embedded.

 You should be able to rely on tools to show scope, track velocity and project when a release is going to be finished. You use automated testing to ensure quality, (integration, performance, security etc.).

You let the team (usually the Product Owner with input from the development team) decide when to launch the release. They are the ones who know when it is ready to go and will not be a support nightmare due to lack of quality or completeness.

You use IaaS or at least the right tools to ensure an automated launch, ticking all the boxes that need to be done to ensure a successful and stress-free release.

Boom! It should be simple, if you are working in an Agile way (which is the challenging part to achieve). If not, you will disappoint expectations for the release in terms of scope and schedule, fire-drill over every release step, waste time, energy and customer satisfaction with extensive production support after the release.