The internal version is installed inside the DRO-350 enclosure. First, open the back of the DRO-350 by removing the four screws in the corners. Remove the PCB from the back of the enclosure by removing the six screws attached to the hex standoffs.
Unplug the MTA receptacle attached to the PCB for the axis you want to install the QCC-100 on. Plug this MTA receptacle into the QCC-100 MTA header. Plug the QCC-100 MTA receptacle onto the MTA header on the DRO-350 that you just disconnected.
Plug the QCC-100 power connector onto pin 1 of the JP8 header. It is probably a good idea to drop a small amount of hot glue or some other adhesive on the joint between the power connector and the JP8 header so that the power connector does not come unconnected. If you install an additional QCC-100, then daisy-chain its power connector to the one pin JP3 header on the QCC-100 that is already installed.
The QCC-100 can be attached to the back of the enclosure with hot glue or some souble-sided tape. This will prevent the QCC-100 from moving around and possibly shorting something out.