1.put your normal disc in and wait for it to load
2.click X button to go on to details
3.you should see a little red laser on disc wait few mins for that to stop and turn off
4.take out your normal disc quickly and replace with your ISO disc
5.click install and wait for your modded disc to install (needs to be done fairly quickly)
6.put your normal disc in and simply have fun playing modded game!

This is for latest dash so works online! But same steps for ever other dash so its fine either way,
Feel free to add me on TTG,
Or on xbox live, GT: iOwennnDx

Very basic tutorial but its there only 7 quick easy steps, easy to follow
Thanks,
Owen.