How can I safely get off of benefits?

Hi, I'm on new style ESA (support group)and UC.
First, Thank you so much for your help over the years. The guides on this site have helped us get our survival pittance for a long time now. I don't know what would have happened otherwise. It's hard to overstate how important it's been for us.

But I want out of this nightmare.
I have had it with being treated like vermin for accepting money I'm legally entitled to.
I've lived like this for over three decades. I would rather be destitute than live like this anymore. I have friends and family who'll help some and my disability will be easier to manage than it ever has been without this imposed stress. As it happens, a good friend of mine has come into some money and has has already agreed to help how they can. I can live cheaply as all my hopes and dreams have been crushed and I don't really want anything anymore except to be left to my own devices

So, since simply ending my claim is considered a red flag how should I go about decoupling myself from their system?
What are the specific criteria for ending my claims and getting off of their hit list?
What wording should I use when telling them to piss off forever?
Losing some but not all of my benefits would be the worst of both worlds, can I ensure that I'm out of their crosshairs?
I definitely can't afford any fines or charges, so there's also that.

I recognise that this is the opposite of what we typically do here but who else will know the answer?
The CAB will tell me what the law is but you know their system.
Surely I have the right to not take the money even though I'm entitled to it? How do I make myself not entitled to it without getting myself or anyone else into trouble?

Thanks again