Your best bet isn't to remove anything. Just remod your system using our Softmod Any Wii guide (link in my signature) on top of whatever state your current system is in.
Just start at the top and work your way down. Following the process exactly as instructed will update everything that needs to be.
When done, any channels or app forwarders that you don't want can be deleted using Wii Settings -> Data Management -> Channels, then find the ones you don't want and delete them.