I have to replace the drivers side window lift motor 99 Toyota Sienna and am looking for some tips from someone who has done them.

You might want to open up the driver side door and "Take a Look" Toyota does a good job of making some things pretty easy to do.

This will at least give you a look into what to expect, another option is to pick up an or look through a book on your car at a local auto parts store, this way you can see if you will have any trouble.

 Is the window down and dead? Can you lift the window by hand? Never worked on a sienna, but most of the time the motor will be behind the window when down and reachable through panel access. Don't be afraid to get rough with the panel it will have retractable ridged rivets. Disconnect the electrical and the panel should come right off. I don't know how many screws there's be, never more than seven.
That's about it.

This is an old thread,probably already repaired,but if i may add.....

DONT Get rough with the panel,some panels have hook type retainers that are easily broken.
Take the time to carefully remove the panel unless you dont care if something breaks and its loose and rattles after the repair.

Just my thought!

I certainly wouldnt want someone getting "rough" with my vehicle..where do you work so we know!

Jim