Firstly, hats off to the experts !!
I did step1 successfully and then realised that the card does not have 512 MB free.
the total capacity is only 483MB out of which the used space is 26.5 MB.
The folders/files on it are apps bootmii private and so on.....
In short I have done the following 2 successfully
1. Installed Bootmii as boot2
2. Installed Homebrew channel
Now can I use a different SD card with more capacity as this one is short of free space.
Say I copy content of SD card from the one used before to the new one ?
Also, for Homebrew to work do you always need the SD card inside the wii ?
In other words do you need an SD card permanently for the wii ?
Thanks in Advance !