Hi, For the compressor all you do is take a towel with luke warm to warm water soaking it. Make sure to squeeze the extra water out. If it need to be a little warmer then put it in to microwave for a min. Then lightly put onto the injured spot. Leave it on (if you can cause he may want to try to move) for 10-20 mins. at least 3 times daily. It will help with the pain a little bit and any swelling he may have. I hope your dog feels better soon.
Oh and another thing, if you notice him starting to shake He may have a low grade fever. Another thing you can do to help the pain is giving him 1/2 tablet of buffered aspirin. It will help with the pain he is going through. I hope this little bit of information helps.
Annie The Pet Nanny