Git-Hub Push Error

[John Storm]

Mahmoud, 

I am trying to push into git to update a file but I get this:

Authentication failed. You may not have permission to access the repository. Open options and verify that you're signed in with an account that has permission to access this repository.

Everything seems fine, I am using the Git-Desktop, if I try to upload a file through Git-Web I get a error:

Uploads are disabled.

File uploads require push access to this repository.

How do I add the changes to github?

[Mahmoud Fayed]

Hello John

(1) Fork - to get a copy from the project - work on this copy, add commits to it
(2) Once you finish your modifications, Send a Pull Request and I will accept it.

Greetings,
Mahmoud

[John Storm]

Thanks Mahmoud, just gave it a shot and sent the pull request.  

[Mahmoud Fayed]

Hello John

You are welcome :D

Greetings,
Mahmoud