Best way to write a job application when you are applying for a job that is a couple of steps "backwards" from your current one?

[forcedfun]

I had a promotion a few years ago and loved it, albeit not quite as much as my original job (technical specialist promoted to manage large team)

I've since developed a chronic condition and would like to go back to being a technical specialist. I can work full time and hard but just physically cant face continuing with the relentless pressure and pace of this manager role (public sector so pressures are enormous).

I'm just not sure how to present that in a positive way? And ensure people aren't put off by my current role?

Good question and did something similar. I'd drill down into the positives that apply to this particular opportunity and company. It could be:
"Having had the benefit of X years as a senior manager, I want to put my focus back on Y skills, as I believe this is the area in which I most excel." You could add why your experience in your prior role will make you even better (you have a greater sense of the overarching strategic goals? Of the pressures on management?).

I think it's probably verbally fine in an interview to acknowledge that you want something less demanding on all fronts but in the environments I've worked in, I'd think twice about proactively mentioning perceived limitations (why focus on what you can't do versus what you very clearly can) but others may advise differently.

FWIW I think best to acknowledge it in a cover letter, so they understand the logic and don't toss it aside under that most ridiculous heading of "over qualified".

I think you need to address it at the point of application so they understand your reasons for applying for a job you're very overqualified for. As you're a manager you probably understand the recruitment process so put yourself in the hiring shoes and think what questions you would be asking of the applicant.. anticipate these and acknowledge them in your application or a cover letter

I think you can say something about wanting to return to the role you loved, the reason you entered the industry, getting back to being directly customer (or whatever) facing, maybe even something about how having the management experience will enhance your ability to perform in the old role.

Thank you all, this is really helpful.