Install PCBmodE. Clone this repo into the "boards" directory within your PCBmodE installation.
Generate the Board
pcbmode -b sdvx --fab -m
You should now be able to view the board SVG in /sdvx/build/sdvx.svg.
pcbmode -b sdvx --fab dirtypcb
Board files will be output to: /sdvx/build/production/
Modifying the Design
In PCBmodE, there are two different ways to modify the design: the sdvx.json file itself, or the sdvx.svg output file in the /build/ directory.
The json can be used to define/place components, while the svg can be used to place traces and move components.
After modifying the json, regenerate the board with the -m flag.
After modifying the svg, extract the changes with the -e flag, and then generate the board with -m.
For more info, check the PCBmodE Wiki.