Is it possible to replace uploaded assets? I have a site that uses several PDF forms that update from time to time. Instead of adding a new asset, I would rather replace the existing one.

I couldn't see how to do that from within the Craft admin. I suppose it's possible to do via FTP, but I'd really like it to be able to be done by the client.

Am I missing something, or is this not possible at this time?

Thanks
This actually is possible if you navigate to the folder or sub folder where you are trying to add the asset and then upload a file with the exact same file name.

Craft will ask you if you want to replace the existing file or upload another version with an appended name (for example "my-file-1.txt")