How do I transfer a file from a guest account on a MacBook Air? I'm logged into the guest account of a borrowed MacBook Air which is running OS X Version 10.9.2 and I've been trying to transfer a 2.19GB video file to an admin account, a USB or external hard drive, or online. 

1. Transferring the file to the admin account:
Apparently if I log out of this guest account, the file will be deleted. So, I tried transferring it to a shared folder, but I can't find/access a shared folder... perhaps because I'm on a guest account? I tried using Terminal and codes I copy-pasted from Google, but they all require the password of the admin account, which the owner can't remember. We've been working together the whole afternoon to try to remember the password, but the owner says he'd be able to guess it if he had the "password hint". Unfortunately, we only know how to view the "password hint" by logging out of the guest account, which we obviously can't do, or else the file will be deleted.
Transferring to the admin account: FAILED :(

2. Transferring the file to a USB or external hard drive:
I've tried both ports with 3 different USB's, and none of them were recognized by the Mac. I've also tried plugging in a WD external hard drive in both ports, but neither recognized the hard drive. All in all, nothing between 3 USB's and 1 external hard drive showed up on the Mac. Could this have anything to do with being logged into a guest account?
Transferring the file to a USB or external hard drive: FAILED :(

3. Uploading online:
I've had two tabs open for the past 15 minutes: YouTube and Google Drive. Neither are showing any progress towards the upload. As I'm typing, both currently remain at 0%. I've also tried uploading the file through email, but Yahoo crashes before the upload even begins. In addition to this, I've tried uploading with Filemail.com multiple times. Each time it says it has "problems uploading"...
Uploading online: FAILED :(

Is there anything I can do? Is there another method I can try? Perhaps theres a way to view the password hint without logging out of the guest account? Is there another way to access the "shared files" folder without needing the admin password? Is there anything that can be done about the USB's and the hard drive that won't show up? Is there a reason why the file won't upload online? I would really, really appreciate your help. Thank you in advance!
Every user account on OS X has a public drop box folder inside its Public folder (path is /Users/USERNAME/Public/Drop\ Box/). So what you can do is download the file into Guest's Download folder and then copy it (via Terminal or Finder) to /Users/ADMINNAME/Public/Drop\ Box/. You will get a warning about not being able to access the file after the copy, just click ok there.

Alternatively you could move the video to /tmp and then switch accounts. Files owned by guest are not deleted from /tmp if the Guest user logs out.