The socket is known as a Marushin. where to fit it is probably best where it can fit well on the rear panel and is not interfering with other cables or mechanisms, also where panel thickness allows. . Start with a 6mm bit then a 10mm then a 13mm and finally a 16mm. Thank yourself you are not drilling XLR style sockets as these are 20- 22mm
If it is a DC fitting you are doing, be aware of DC polarity. A fail safe is to install a forward biased diode like a 1n4004 which is rated to 1 amp of current, or if more current a 1n5404 which is 3 amps. the makings on these diodes is the silver line shows the cathode meaning the destination end. the diode if forward biased will drop voltage approx 0.4- 0.7v
Hope that helps. / Chris