You can upload your files to sendspace.com and share the download link with your expert via order chat.
It is a free service that you can use without registration.
Please follow the link and do the following:
Click on the Browse button to choose a file from your computer
2. You will be forwarded to the Select files page.
Important: you will see To/From fields. There is no need to fill them out - just click on the Upload button, and it will go through.
3. Click on the Copy link in front of the Download Page link to copy the link to the file and send it to the expert.