You have been directed to multiple sources of help. You refuse to read them. I doubt anyone can or would give you a step by step tutorial when you refuse to even answer questions needed to understand how you got yourself into this situation.
Please, don’t blame others for your ignorance.
You previously wrote this:
Booting with the Manjaro installer as described solves that problem.
What is so hard to understand?
I was trying to get help to access and get permission to my external usb drives that no longer let me rename files, or copy paste anything to them for some reason and nothing i try works.
One suggest ed i try this command
sudo usermod -aG storage $USER
which now afterwards i cant boot my pc anymore without going into some safe mode black screen stuff i cant get out of again, unless i plug in a drive?!?
I just spent and hour tryign to start my pc, this is doing more harm than gd 
Can someone pls tell me how to revert this command so i can start my pc normally again pls?
Ty
u just had to do it right? my point proved, this is the type to help u get on manjaro forums, arrogant obnoixiours knowitalls who just has to have the upper hand and tells u to uninstall manjaro.
There are real ppl asking for help on the other side of this screen and u just slap them in the face.
U push untill u get the provoked answer so they can close the topic and u remain looking gd and right, right?
But im glad ur gd.
The thread is going in wrong direction, unfortunately and therefore closed here.
gpasswd -d "$USER" storage
Although I highly doubt this has anything to do with your problems.
Hi ty, do i need to be logged in as su for this to work?
It didnt work no, i still cant rename or copy paste to any usb device.
And how do i revert that as well pls?
It did nothing so far so now i fear it just did more harm than gd :s
I told you how to revert that command, not how to do whatever you have problems with. This last post of yours have nothing to do with your first one.
Ok ty, if its like it was b4 that other command i was givin then i asume its reverted?
I thought u were giving a command to try to gain command over storage, as the 2 commands didnt exacty look like a mirror opposite.
And because it says im removed from group storage, which i thought i shouldnt be as root?
Ty
What do you want me to spell the first command backwards? Maybe it’s time you start reading what commands actually do and how to do the opposite. You know, all exists on the internet you just have to type it in some search bar.
Best advise!