on template 12 cutout region 18 represents the segment of cancellous bone 63 to be removed by a bone miller 50 bone miller 50 is inserted downwardly into bone milling guide 10 along the axis of cavity 15 until rounded tip 52 is received in socket 16 bone miller 50 is then moved in an arcuate path with guide follower 56 following the profile defined by sloped surface 20 of template 12 while rounded tip 52 is held in socket 16 the movement of bone miller 50 in this arcuate path allows milling surface 54 to remove all of cancellous bone 63 in cutout region 18 providing cavity 80 with an enlarged cavity 82 as defined by dashed line 19 and also as shown in fig7 referring now to fig7 bone milling guide 10 and guide 30 have been removed from bone 60 leaving a precision machined cavity 82 which in combination with hole 65 is prepared to accurately receive the preselected hip stem not shown in snug fitting relationship advantageously hole 65 and cavity 82 are prepared quickly and accurately in comparison with the prior art techniques and more importantly with a far superior degree of precision referring now to all of fig1 7 the procedure for using bone milling guide 10 is described once bone 60 has been surgically exposed the ball portion thereof not shown is removed according to conventional surgical techniques leaving intact as much of the greater trochanter 68 as possible importantly the calcar surface 62 is.