How do I remove iCloud files downloaded to iPhone?

Sorry, that's not it. I have no trouble accessing my iCloud data on my other devices. No problem there: not my question. Nothing to do with other devices, or iCloud, just my iPhone.

I want to get the iCloud documents and files OFF my iPhone to free up space. When I try to open new large documents on my iPhone it tells me I have too much already downloaded and will not open them. This is despite the fact that when I check my iPhone storage 89.8 GB of 200 GB is used. Simply put I believe I need to remove local iCloud files from iPhone. They and they alone are preventing me from accessing other files on iPhone.

I know how to turn off iCloud Drive on my iPhone. Pretty simple, easy to find. When I turn it off and go to Files all I see is "Turn on iCloud Drive." When off, I do not see the synched data. I do not see the "On My Phone" data in the Files app.

As per the link you provide for freeing space - which again I can find easily - is EXACTLY where my problem is. iPhone > Settings > General > iPhone Storage shows the vast majority of stored data as "iCloud Drive" even when Drive is off. I conclude this is the iCloud data stored locally on iPhone preventing me from accessing additional files. I want that gone, a fresh start. When I look at Settings > General > iPhone Storage > iCloud Drive I have 22.22 GB used on my iPhone as Documents & Data. There is no way in this place to know WHICH documents and WHAT data are gumming up the works, and no way to erase them. I only see how many GB are used by iCloud Drive: 22.22 GB.

When iCloud Drive is on, and Files app is available, there is no distinction between which files are currently downloaded on my iPhone and which are not. I cannot make a determination which to erase, or how to do that just on the phone and not disturb them in iCloud storage. I do not see "On My iPhone" anywhere.

Recap:

No problem with files access on other devices. Non-issue.

No problem turning off iCloud Drive on my iPhone. Easily done.

With iCloud Drive off I do not see "On My iPhone" in Files app.

With iCloud Drive off the Files app says only "Turn on iCloud Drive."

With iCloud Drive off in Files app no further function is available. Dead end.

With iCloud Drive on I do not see "On My iPhone" or any other indication in Settings or Files app of which documents are in my iPhone storage, or how to remove them.

In iPhone Storage > iCloud Drive I see no option to identify or delete files, only the GB used.

SO...

I'm asking:

IF I turn off iCloud Drive on my iPhone (but not sign out), and

IF I delete Files app from my iPhone,

THEN I turn iCloud Drive back on, on my iPhone

AND I download Files app again from App Store

WILL the data file names (and the names only, NOT previously downloaded documents) synch and repopulate my Files app for access?

AND will the large data used locally on iPhone be removed successfully, freeing space and allowing new documents to be opened on iPhone (downloaded)?

Again: I got my thinking on this from a 2016 post: https://discussions.apple.com/thread/7685762

BUT I don't want to risk this on a much later iOS than the one referenced above without guidance. I don't not want to remove files from iPhone, turn Drive on, and have the synch function work backwards and remove them from iCloud itself, or any other mishap with my data.

Perhaps this?

I could store a copy of my iCloud data on my Mac, erase the whole thing on the cloud, delete Files on my iPhone, then put the cloud files back on iCloud, then download Files app again on iPhone, then let iCloud synch again with Files, leaving no iCloud data on iPhone. Again, I would like guidance before screwing all my data up forever.

I hope this spells out my issue better.

Many, many thanks for your attention.

Well dang.  Things have changed.  So disregard that previous reply and focus on this one, please.

I followed your advice and I have a new problem.  My files won’t open.  

I turned off iCloud Drive.  I couldn't access anything in Files app, only the message "Turn on iCloud Drive." I turned iCloud Drive back on again.  Back in Files app I saw no iCloud Drive files.  I think it just needed time to sync.

However, when I looked in iPhone Storage > iCloud Drive with Drive off NOW there was an option, not available before, to delete the 22.22 GB used by iCloud Drive.  The prompt said they would be removed from my iPhone, but not from iCloud itself.  I chose the option.  POOF the 22.22 GB used by iCloud Drive disappeared from iPhone Storage.  Progress.  But not.

Now in Files app my files appear.  But they will not open.  I can see them all in thumbnail form, curiously, but not when I click them to open.  Photos say “file couldn’t be opened.”  Documents enlarge on the screen with the name, format, and memory used, but they don’t open. 

I deleted Files app twice, waited for it to sync, and got the same results. I waited overnight: same.

A search "my files in Files app will not open" turns up lots of irrelevant information, all about how to use Files app as if it works.  Modified searches are the same.

So now what?