How do I delete Dropbox files without deleting them on my hard drive?

Hi Rich,  Thank you for your response.  I found the following in the link you provided:

To turn off computer backup:

1. Click the Dropbox icon in your system try (Windows) or menu bar (Mac). 
2. Click your profile picture or initials.
3. Click Preferences.
4. Click the Backups tab.
5. Click Manage backup. 
6. Uncheck the folders you’d like to stop backing up to Dropbox or uncheck My Mac_My PC to turn off backup for all folders at once. 
7. Click Save.
8. Choose Keep content in folders on this PC/Mac or Leave content in Dropbox

• If you choose Keep content in folders on this PC/Mac, the files and folders you stopped backing up can be found in their original folders on your computer. 

However, I was not able to follow the suggested step past Step 3.  I have the app downloaded on my desktop and I was not able to go that route either.   I never find any Backup tab etc... ?

 I know under "personal Account" and "General"  in the Desktop My Dropbox app it is very clearly pointed out that if you DELETE my Dropbox than your data wil lbe gone forever.

But what IF I took another route and instead under Security tab What if I were to simply TRASH the Devices that Dropbox are linked to?   In theory then they wouldnt RESYNC to those devices until I asked it to - then at that point I can hopefully pay a little more attention and be selective about what I allow Dropbox to Sync up with.

I am only hesitant as I dont want to create some mess where my files no longer become accessible/readily avail on my hard drive -Im paranoid about this for obv reasons but alos because I have searched all over and have not found a solution nor have  I seen that other have been able to find a solution as to how to resolve the issue of hard drive files getting simultaneously deleted whe nthe yare removed/deleted from dropbox account.  OF course, Dropboz conveniently has "Upgrade account links placed ALL thruout the various pages in different locations - all for a monthly bill of course"

In short, I want to use the free version for a while to see how it goes with work projects - but  i DONT want everything from my C drive on there - I just want the essentials - in the future if I gain enough confidence in the program then maybe  I can upgrade and bring a lot more over - but this is not likely unless I can resolve this issue...

Do you think a reverse engineer approach of TRASHING/removing the Devices that Dropbox are linked to on Dropbox.com might do the job - without deleting everything off my hadr drive? 

Thank you for any help ... really appreciate any guidance on how to remove everything that I accidentally transferred over - any solutions short of having to create a whole new account would be greatly appreciated