the files does not need to be extracted or anything like that.
1.download this file:
PC36IMG RA 2.3.zip and rename the file to PC36IMG by deleting the"_RA_2.3 part of the name. do not add a ".zip" to the name as windows hides extensions.
2.move the file over to the root of the sd card. and then go to hboot (power off then press and hold power+vol down).
3.hboot should see it and select yes to update.
4.it should do its thing and before you reboot select no to go into recovery
5.make a nandroid backup.
6.select the first three items to backup and then select wimax as well.
you should have at least one nandroid backup with wimax saved onto your computer, just in case something goes wrong and you loose your wimax keys. once they are gone you can't get them back unless you have one backed up in a nandroid.