Just in case someone else runs into this "issue"...
I let the motor sit fully assembled for 24 hours and the hla's bled down on there own. I don't believe these have a check valve in them, nor do you need to refill them like you do with the rocker style hla's that you find on the phase 1 ej18 and ej22.
When you reassemble the motor, its perfectly normal to have all of the valves cracked open 1/8" to 1/4". The hla's, specific to the 1996 outback USDM EJ25D motor (might have been used in other markets, but this is the only motor and only year these were used in the USDM) will need to be given time to bleed down before you attempt to start the motor. I suggest leaving the intake manifold off so you can visually verify they have bled down...