Clever tool from BGM for damage free installing of studs. Come as a set of 3 - M6,M7 and M8
 
Screw the tool onto the stud and turn the socket screw with an M6 allen key, this locks the stud against the nut. Now turn the outer hex head with a 19mm spanner. The stud is fixed and can be loosened or screwed in.
 
Ideal for short bolts (eg Lambretta endplates and chaincase side).
 
NOTE: Please note any studs glued in with Loctite often have a very high breakaway torque. Here you should try in advance to heat the studs or the housing around it to loosen the adhesive.