of course it works. Refer to the HP A7500 Switch Series Fundamentals Configuration Guide. (It's actually a good reference for this!) Starting on Page 119.
You can easily TFTP the Boot Rom file, as well as the new Switch O/S.
Once you get the new files uploaded to the Switch, you use the boot-loader command to set the switch to use the new files.
Also, once you get upgraded, you should look into the ISSU Feature. This allows future upgrades to take place while the switch is running with no hard reboot.