Angel fish are happiest when there is apir per 30 gallons of water. Now lets say you went out and bought something like a 55 from walmart. You get it setup, cycled, decorated, etc. the best way instead of trying to bag the fish is use a drip acclimation. Don't be fooled by the pet stores, you can easily make a drip acclimation tube for literally pennies lol. heres how to make one:
take a piece of airline tubing around 6-8 feet long and cut it in the middle, then go out and buy a plastic control valve from the pet store, its justa simple valve that connects into the hosing and has a screw you turn to restrict airflow, in this case it will be water flow.
join it in between the 2 pieces of tubing and you have yourself a drip tube.
the process: Get a 3 gallon bucket or 5 gallon and fill it about half way with water formt he 10 gallon. gently place your angels in the water in the bucket. move the bucket to your newly setup and cycled tank. place one end of the airline tubing in your new tanks water, you can use the hood to help hold it in place, or you can tape it, just so it stay under water about 6 inches. screw the control valve all the way down, then bring it back up about 1/2 turn, this keep water from siphoning into your mouth to quickly lol. give a quick suck on the other end to start a siphon, place the end you just sucked on in the bucket. Use the control valve to regualte a flow of about 3 drips per second. Let the bucket fill up the rest of the way. this mix's the existing water from the 10 gallon in with the new tanks water and gives a more suitablke acclimation. I twill take a few minutes to fill up. Be sure to keep an eye on your angels, i fthey start getting stressed you can turn out the rooms lights to help them be relaxed. once the bucket is full and you let them set in the mixed water for about 15 minutes its ok to move them in the new tank, I highly reccomned netting them in the new tank so you don't splash water everywhere, possibly mess up your tanks parameters, etc. Also if the fish are gasping at the top before its over you can run an aristone in the bucket to supply oxygen. HTH