I always have a difficult time getting the hops in the carboy and then removing it when dry-hopping. What's the trick?
The easy answer is don't use a bag. I usually use whole flowers when dryhopping. They float on top and then I rack to another carboy when done w/ the dryhop.
I used a bag 2x and it was a royal pain in the butt. Getting it out was always the hard part, brute force was my method. It always made me worry about contamination.
It's easier using pellet hops in the bag. What I do is place the hops in the bag along with a weight of some sort (a stainless butter knife or something thin) to get the bag to sink. Tie a length of dental floss to the top of the bag and lower the bag into the carboy keeping a length of the floss outside the carboy. Lower bag halfway down and then push the stopper/airlock back into the top of the carboy cinching the dental floss in place so that you can pull the bag back up later. I would recommend racking the beer out of the carboy before trying to retrieve the bag because it will expand and need to be worked out of the carboy opening.