No, it is not hard, assuming you can find a new mag safety. I believe the one for the BHP will fit, but won't swear to it. You also need the spring and pin, as I would assume they are missing as well. Take out the trigger and clean up whatever needs cleaning, then insert the safety, spring and pin, making sure the trigger lever is activating properly.
A lot of folks like to remove that mag safety, but I advise against it; I know the problems with trigger pull, but IMHO removing any safety device is not the best policy.
Jim