As long as you are absolutely needed, chances are your managers will resist a promotion or a move to a new role where you won't be present any longer.
As long as you are absolutely needed, people will call you when you are out of the office (which is unacceptable for you); or they will have to wait until you come back (which is unacceptable for the company).
You should aim for things to work without you - at least for a week or two (more than that and you are probably talking yourself out of a job).
Start with the little things, stuff that can be automated or delegated (to one person to a collective group ... there is a lot that can be crowdsourced in a team).
You will still be needed to ensure things run smoothly and to maintain/update the systems you put in place, but that is much lighter and occasional work.
When the lilttle things work without you, you can take on more complex work, more interesting work (which is good for you). That king of work usually generates more revenue and increases the company's reputation (which is good for your employer).
And when you've done that, see how you can help others (especially your reports) get there too.