ps. Also picked up one for Fantasmic, cant find any info of this. its only 3 hours. no clue where to go, or where costuming even is. eek!
Costuming for DHS is in the cast services building right by the CM parking lot (Television). Once you go through the front door, costuming is on your left. There are changing rooms at the back of the rows of lockers.
If I remember correctly (it's been a long time), the meeting place for Fantasmic is a trailer behind Tower of Terror. Getting there can be a challenge, I know how to walk it, but I don't have a good description of it. (I'll try anyways ...)
Basically, go RIGHT out of the back of the cast services bldg to the main entrance, cross onstage to the Oscar's gate, make a left, go onstage, cross Sunset Ave and go backstage near the cafeteria (Take 5), then walk through the parking lot, go onstage again near Rock N Roller Coaster, cross the coaster courtyard to the gate behind the queue entrance, go backstage, walk around Tower, and then you're there. (It sounds like a long description, but it's really only about 7-10 minutes)
(The other option is much easier, but much slower, probably about 35 minutes to walk ... go LEFT out of the back of the cast services building, and follow that road all the way around the outside of the park ... past Muppets, past Lights Motors Action, past Catastrophe Canyon, past the Engineering building, past the tram parking area for the backlot tour, past the parking garage, past the RNR parking lot and finally to the Fantasmic Trailer. Trust me, you do NOT want to walk this way ... but, if there's a bike available and it's still light out, it's not a bad bike ride ... maybe 7 minutes)