User: failry simple ..Do not overcomplicate the entry point
Root: 2 steps!!
The first step requires a similar attack as that of user & hijacking a service
The second part : helps if u have done Helpline Box
Don't know exactly what your comment means ,but as far as retiring boxes are concerned generally the boxes on top of the active machines section get retired;
There are other factors too,like the boxes with highest number of owns or difficulty etc;