1. go to your .minecraft file (by going to run and typing %appdata%)

2. click on saves

3. copy the file of the world you want to upload

4. paste it into the desktop

4.5 right click and go to send to, then click zipped folder

5. go to http://mediafire.com in your browser

6. make a free account (unless you already have one.)

7. click upload

8. A new window will open. Click on the fading box with a cross in it.

9. find the zipped file in your desktop

10. double click it

11. then click upload the file. wait for it......

12. then right click and copy the link

13. paste it into the "website download URL" (in PMC)

And click save! Dont forget to change your update log!