N Connector, whilst the standard bulkhead mounting type of connector can be mounted on the outside of the case a better result can be obtained by mounting from the inside.....

Using the ideal type of N connector, a small amount of filing of the PCB is necessary to accommodate the flange on the inside of the case. The ground connection is made by a supporting bracket underneath the PCB (outlined) this is a part of the connector itself.

Using a cheaper type of N connector, the flange can still be accommodated on the inside, but take care when filing the PCB as a much larger amount of material needs to be removed. In this case the ground connection is made by flow soldering directly to the tinned back of the socket - make sure that the inner plastic (best to use PTFE type) doesn't melt - have a plug fitted, in the socket,  whilst soldering to stop the pin moving around as well!.

How to bend the trimmer legs; 
use a pair of long nosed wiring pliers, whilst pushing towards the trimmer bend the legs at right angles, finally cut the excess lead length off.