An apparatus for performing surgical procedures is disclosed including a flexible entry guide tube and a first steering device. The guide tube has one or more lumens extending along its length from a proximal end to substantially at or near a distal end. At least one of the one or more lumens is an instrument lumen with open ends to receive a flexible shaft of a surgical tool. The first steering device is insertable into the instrument lumen to shape the guide tube as it is inserted through an opening in a body and along a path towards a surgical site. The apparatus may further include a flexible locking device to couple to the flexible entry guide tube and selectively rigidize the guide tube to hold its shape. The guide tube may be steered by remote control with one or more actuators.