This tool by Lisle has three sizes of slotted tubes for working on different sizes of Deutsch terminals (12GA,16GA,20GA) and works well with our bulkhead connectors. Slotted tubes are made out of stainless steel which work and last longer than plastic tools.
This can be used to insert terminals as well as remove
TERMINAL REMOVAL: Slide appropriate size slotted tube over wire. Push tool into grommet, it will bottom out on the Deutsch terminal. Do not twist tool. Pull the wire terminal out of the connector. If the terminal does not come out, pull the tool straight out and rotate 1/4 turn and repeat the process. Use care as to not damage the connector, it does not take great force to remove the terminal.
TERMINAL INSTALLATION: Simply slide the terminal tool up to the shoulder of the crimped terminal and slide it into the connector until it clicks. Gently remove the tool. (Tool is not always needed to install terminals, some smaller 20 ga wires can sometimes need a little help on insertion)