Maishy. Do you mean directly to the camera? If so, I would doubt that you can.
AFAIK - from doing this quite a few times over the years - cameras are "programmed" to look for
firmware update files in the root directory of their storage media (mine, a mix of SD and CF cards).
So basically I would:
1. Download from site to computer.
2. Copy file (after running a good security check over it) to appropriate storage card...
- you can either hook the camera to computer by USB cable, or put the card into a card reader...
- paste the copied file straight onto the drive letter - eg, say "E: Pentax"...
3. Put card into camera and switch on, then find your firmware update menu and follow it.
NOTE: the process can take a few minutes, and my camera settings WARN me to make sure I have a full battery
before proceeding, so that it doesn't crash out and - &%*&*^#*(&40(*& - who knows what?!
Ie, it's a cakewalk.
- - - Updated - - -
PS: The update file does not take up much space, and you can delete it later if it's a problem.