Charity,
Thanks for asking your question to planDisney!
The walk from the entrance to
Disney's Hollywood Studios to the
Droid Depot is about 4/10 of a mile (700 meters), which would normally be about a 10 minute walk. Because crowds at opening times can be a bit thicker than usual, I would give yourself at least 20 minutes for the walk. Who really wants to rush when they are on vacation?
Even with just a 20-minute walk time, I would still make sure I was at the gate at least 45 minutes ahead of your reservation. While getting through the turnstiles is far faster these days, you will still be slowed down by larger crowd sizes, so you will want to account for that. Since the park opens at 8:30 am, I would suggest that you be there as close to the famed "rope drop" opening time of the park, say between 8:30 am and 8:45 am. A reservation for Droid Depot is a cherished experience by many, and you just don't want to miss it!
Write us back if you have any follow-up questions, and say hi to R2-D2 for me if you see him!
Have a Magical Vacation!
Doug