First start by cutting the top of the bag

Next carefully pour the beads into the applicator bottle

Cut the end off the cap and install onto the Applicator

Thread the plastic hose onto the valve stem all the way down

Attach the bottle to the hose

Now the important part:

Slowly tip the bottle up until you get a slow, steady stream, don't rush it.
If you try to rush things, it will jam up. If it does, lower the bottle and tap on the valve stem until it clears, then start slowly again.
There is a way to eliminate the jamming and speed things up by using a vibrating tool, see farther on down.