Sure, that is not difficult. Have you softmodded your wii, install cios?
You can start downloading
anyregion changer mod06 for 4.1 by qk offline
password is QK.Mod
If you have cios38 (ios249) installed, format your sd-card and put the above anyregion changer onto it. Load the app from HBC and use ios249. You will first set all of your settings to euro or usa, whichever you like, also set elua to read. Be sure they are all set as they should be, they push SAVE. Then below that install system menu 4.1u/e, be sure to pick the proper region.
You have now region changed your wii.
Use dop-ios-mod to install any channels you may wish to use, like shop, etc.
Use "any title deleter mod db" to remove any jap channels you wish not to have.