I always go with copying from a tftp server, since I have one running all the time to PXE boot things.
Then look in the release notes pdf for the fw version you are updating to. Probably on page 2 it will say something like:
ProCurve switch # copy tftp flash 10.28.227.103 M_08_8x.swi
The primary OS image will be deleted. continue [y/n]? Y
03125K
The 10.28.227.103 is the IP of your TFP server, and M_08_8x.swi is the frimware image you downloaded form HPEs site andunzipped and put on the tftp server.