the cost to repair might be higher than the actual cost of getting a new watch, but the watch might have sentiment value to you i guess..
watch face is something like this part right?
i haven't personally tried, but Mr. Goh @ K2 Watch Katong has been receiving rave reviews for his service..he does modifications for Seiko watches, so you can give him a call to check if he is able to do what you want..
https://www.facebook.com/pages/K2-Watch-Co/182964558422077
the problem is, changing of watch face = you need a watch face to replace it..not sure how u gonna find another watch face