As far as getting the sand out, since you probably don't want to move rocks/fish/etc, just siphon a little out at a time with water changes.
And I know you didn't ask for it but I'm going to give my opinion anyway lol. Getting rid of the sand is a good idea for small tanks BUT I think is looks bad. I've seen people get this thing called starboard (I think just a cutting board, which you could also use) and cut it to fit in the bottom of the tank.
The guy I saw cut it smaller than necessary and all the debris collected around the edge like a poop moat.