You can follow the guide and start where is says "with homebrew already installed" however it won't do any harm to start from scratch. A lot of progress has been made since your last mod. DVD backups are still able to work if you have gamecube ports, but, usb loading is far superior. I'm unable to link guides as I can't seem to get it to work from my phone but there are guides for wiiflow, USBLoader GX and a FAT32 guide is also a good place to look after you've modded your wii. You may also want to check out the usb compatibility guide.
Find the guides in a mods signature.