I mounted the front and rear rocket activation handles and routed the cables back to the chute tray mount. Similar to a gun, these cables, when pulled, actuate a firing pin at the rocket, which detonates a primer, which then ignites the sold fuel rocket. Since both cables are connected to the firing pin, they provide some redundancy, should one fail.
I then assembled and mounted the rocket assembly to the tray and connected the rocket lanyards to the chute. The lanyards (not shown) will pull the chute out of the plane on deployment.
The rocket is housed in this launch tube with cables and firing pin at the bottom.
The rocket would exit the top of the tube and pierce the fabric on deployment.
The four airframe bridles are all attachedt to a common carabiner. From there a single bridle runs to a carabiner which is connected to the parachute.
Some additional pics showing bridle routing: