Door panel removal can be tough if you havn't done this before and I recommend you get a repair manual if your going to work on your own vehicle. It's real easy now that they're available online. To be better prepared when working on your vehicle, read up on the job you're about to perform, it will show you component locations, bolt torque settings and what special tools you'll need. There are also technician tips related to your specific vehicle.
Try http://bit.ly/mitchell_repair_manuals_online and you can have one in minutes, for less than $30.00. or you can check repair estimates here http://repairpal.com/estimator?car_type_id=1610 and locate ashop to repair this here http://repairpal.com/directory?address=94010&car_brand_names=Lexus