1-Start XeX menu and scroll until u will see your IP address.
2-in PC-Install FileZilla and go to site manager, give your IP that you saw in XEX menu & also in setting select Active mode instead of Passivie. your IP may be like 192.168.1.XX
3-in PC-Install XBOX GUI, select FTP and connect and on left side select HDD1/Games
4-Then select iso and extract it, you will see in XeX transfering of data.
5-after extraction, go to HDD1/Games/ and run your game with *.xex fie.
Note: during extraction your XeX menu should remain opened and you need to connect your xbox with Ethernet cable of your router
OR
Use the USb.
1-format it with Fat32 or let xbox do it for itself iin storage setting when u plug it.
2-then follow from step 3 above.
enjoy