I don´t think it can be explained any clearer than I already did before...
Go to
www.noobz.eu search and download the downgrader that you would like to use and follow the step by step instructions included in the file
Downgrader_HOWTO.txt that you will find within the downgrader ZIP file.
Also have a look at this thread since everything explained there is applicable for you (Similar situation to yours).
The
Downgrader_HOWTO.txt includes a download link for the 3.30 Update file and also explains how to upgrade to 3.03 before using the downgrader.
Come on people!
Don´t be SO lazy.
Do NOT expect us to explain everything again and again when it´s already explained within the downgrader instructions and also in other topics in this same forum.
The answer to ALL your questions is EASY enough to find, just
READ.