A device for guiding the insertion of an instrument having a longitudinal axis into a body of a patient at a targeted point of entry and along a path at a targeted insertion angle, comprising: a base component comprising a proximal and distal surface, a lumen extending therethrough being aligned in a first position during insertion, the distal surface configured to provide stable engagement of the device against the body during insertion, a guide assembly removably engageable with the proximal surface of the base component; wherein the guide assembly comprises: a first element including a first guide hole in fixed alignment with the lumen of the base component, a third element including a second guide hole configured to slidingly accommodate the instrument in alignment with the first guide hole and the lumen of the base component during insertion, and a second element comprising the first guide hole and the second guide hole and a mechanism to adjust and fix the second guide hole relative to the first guide hole in a second position; characterized in that the second element comprises a flexible member including a longer arm portion and a shorter arms portion in a Y-shape, a middle of the longer arm portion including the first guide hole and engageable with the base component to align the first guide hole and the lumen at the first position, the shorter arms portion including the second guide hole and bendable back over the longer arm portion and fixable to the body in order to align the second guide hole relative to the first guide hole in the second position. a base component comprising a proximal and distal surface, a lumen extending therethrough being aligned in a first position during insertion, the distal surface configured to provide stable engagement of the device against the body during insertion, a guide assembly removably engageable with the proximal surface of the base component; wherein the guide assembly comprises: a first element including a first guide hole in fixed alignment with the lumen of the base component, a third element including a second guide hole configured to slidingly accommodate the instrument in alignment with the first guide hole and the lumen of the base component during insertion, and a second element comprising the first guide hole and the second guide hole and a mechanism to adjust and fix the second guide hole relative to the first guide hole in a second position; characterized in that the second element comprises a flexible member including a longer arm portion and a shorter arms portion in a Y-shape, a middle of the longer arm portion including the first guide hole and engageable with the base component to align the first guide hole and the lumen at the first position, the shorter arms portion including the second guide hole and bendable back over the longer arm portion and fixable to the body in order to align the second guide hole relative to the first guide hole in the second position. a first element including a first guide hole in fixed alignment with the lumen of the base component, a third element including a second guide hole configured to slidingly accommodate the instrument in alignment with the first guide hole and the lumen of the base component during insertion, and a second element comprising the first guide hole and the second guide hole and a mechanism to adjust and fix the second guide hole relative to the first guide hole in a second position; characterized in that the second element comprises a flexible member including a longer arm portion and a shorter arms portion in a Y-shape, a middle of the longer arm portion including the first guide hole and engageable with the base component to align the first guide hole and the lumen at the first position, the shorter arms portion including the second guide hole and bendable back over the longer arm portion and fixable to the body in order to align the second guide hole relative to the first guide hole in the second position.