UpdateListItem Web Service to Update Sharepoint Document Library

Question

Good day, I need help please.
UpdateListItem Web Service to Update Sharepoint Document Library
I would like to update the document library from another server/site.
I have no code, i am on a site/ another server to the Sharepoint Server.
How do i create,install a dll on the server to update the list?
How would i call the dll passing parameters in javascript/vbscript?
Please provide code & steps (I have to get this going & have no clue what to do)
Regards