(Not my wording's just pasted as i found it )
first thing to do is format the memory stick in your P910i then go to to the MSSEMC folder and open the P series folder place all the Tom Tom folders in here, (this needs to be done on your computer using a card reader) You need to copy and paste the folders, do not drag and drop as this can cause problems. Start up the phone your new icons should appear for Tom Tom and contacts navigation link to your GPS and you should be good to go.