A method for mounting a sheath onto the distal end of a surgical shaft instrument, in particular the tool tip of a dilation instrument. The method makes handling easy and allows the sheath to be fastened on the instrument in a rapid manner sparing of material, characterized by these steps: a) fastening the sheath on an apparatus for mounting a sheath onto the distal end of a surgical shaft instrument; b) radially widening at least the proximal end of the sheath and inserting the distal end of the surgical shaft instrument into the widened sheath c) transferring the sheath from the apparatus to the distal end of the surgical shaft instrument; and d) removing the distal end of the surgical shaft instrument from the apparatus. The invention also relates to an apparatus to perform this method.