i need help in knowing how to add sids and stars to the database.... and what file to save them under... i also need to know what file i need to put the liveries on thanks for the help

For terminal procedures, the best place is Navigraph (just Google it); although it's a pay service it works out at only 1 Euro to update your entire Navigation database (although credits must be bought in packs of 100 for 10 Euros.) You can spend the remainder on their NDAC Charts, which I find to be brilliant, or alternatively update your navigation database each month for 10 credits.If you really can't afford Navigraph, there are numerous free services avaialable, but they are unlikely to come with an installer.

SID/STARS for PMDG planes are placed into your FS root -> PMDG -> SIDSTAR folder...as yet said, you need to pay the Navigraph service that give you up-to-date procedures every month, for very few bucks...The file to add the liveries is the aircraft.cfg placed into the PMDG MD-11 folder in the main aircraft folder of your FS root.If you have any other question, just ask.Cheers,