With most of the loaders you can use to boot backups nowadays, you dont really have to change anything, just burn it, and play.
However, if you are like myself, and like to change each iso to the proper region and remove the updates too, then first find these programs (google does the job) : Wii brickblocker & regionfrii
In Regionfrii select the ISO and then simply change the region (in the drop down box) to PAL, then hit the 'Update ISO' button.
In Wii BrickBlocker select Browse and locate your ISO, then hit the 'Read Info' Button, Followed by the 'Patch' Button.
When these steps are done, thats the ISO patched, so simply burn it at 2x or 4x, using Imgburner (Again, google is your friend).
Ok, now, for 90% of games that'll be fine, and they'll work fine through any loader (Neogamma is best choice for disc loader, I think). To get Monster Hunter Tri working, though, you need to do a final step (only need to do this once), and that is to use a cIOS that has a base of 37. The easiest way to do this, so that you can load it like any other backup, and not affect the loading of any other game too, is to reinstall cIOSx rev19, and when it asks you which base IOS to use (it'll be set to 57 as default), change it to 37, then let it install, and your Monster Hunter Disc will work just fine.
I hope that info helps you .. good Luck .. :>
