Door panel Rattle drivers side & Muffler Rattle

What is your question?

I just bough a 2001 Boxster S and have the Following Problems: ** Door rattle on the Dirvers side. How do you remove the door panel to see what it is? ** Intermittent muffler chatter. Check for loose brackets found that the muffler need to be replaced? ** How heard is it to replace it? *** Where can you get a good price to buy it?