Here is how I have done it:
The hose (I use silicone tubing) fits perfectly on the faucet output and the beverage-out ball-lock valve. I put hose clamps at both ends to seal it perfectly. The yeast has always been just below the faucet, so not much gets into the keg.
Below is a picture of the top setup. It is a #8 stopper held in place with the ring from an extra faucet I purchased. The white T valve makes the final connection to the gas line. 2-3 psi from the CO2 canister and you're in business.
BTW, I use a #8 stopper with 2 holes in it for fermenting. One has the airlock in it, the other a thermowell so I measure actual beer temperature.