Updating and restoring PDF's in Media Library Outside of Sitecore

Greetings all,

I am just trying to find the best tool for this purpose. A colleague of mine wants to retrieve a PDF that is housed in our Sitecore Media Library, update it, and return the updated PDF back to Sitecore's Media Library. I have been looking at Sitecore's Web api to perform this task, but the documentation is from release 7, and we are currently on 8.2. 

Is this the way to go, or is there a better tool for the task. 

Just want to get the discussion going.

thanks so much