A small case of DeJaVu, It looks you are in the same situation I was in a few weeks ago. I could not find the upload option, so I looked at alternate methods, I had to upgrade it via the command line interface, either telnet, ssh or console. The process that I followed is:
1. Download and install SolarWinds TFTP server (FREE TFTP Server & SFTP/SCP Server) onto a workstation (Same subnet / VLan as the switch management)
2. Download PUTTY and put it on a workstation (Same or different as the TFTP Server, same subnet/vlan)
3. Copy the *.swi file to c:\TFTP Root on the workstation (Or the locaiton specified in the TFTP server install)
4. login to the switch using putty (TELNET, SSH or Console)
5. type the following command:
copy TFTP flash *IP ADDRESS* *FIRMWARE* Primary
*IP ADDRESS* = the TFTP Server's IP Address
*FIRMWARE* = firmware update file
E.G. copy TFTP flash 10.0.0.253 K_12_113.swi Primary
6. Type 'Y' to confirm the copy
The firmware will then upload to the switch and check the firmware
7. when this has completed type 'reload' into the switch.
8. You will need to type 'Y' to restart the switch. You may also be asked to save the configuration of the switch, I will leave this to your judgement to choose your option here.
Once the switch restarts you should be all updated.
Hope this helps
J03