Get ready to chase springs around the room.
I haven't switched out the hammer spring because the replacement is longer than the original, and takes a lot of work to get it in place. I may see if there is a utube video on it. I have some hand arthritis and my grip strength is definitely below average.  Watched the utube on spring replacement, cranked up the vise, and after 2 or three tries, got it installed. Biggest problem was I didn't have paper clip !!! Had to work around THAT issue. DA trigger is somewhat improved, I used a 19# spring.