If it works I would leave it alone until it has issues. You can get parts for replacement. do a search on the internet or check on the forum for vendors. You also can get video's on how to replace it. Youtube etc.
Alright, hmmm...so,just now i borrowed my friend's blackberry and its trackpad is extremely firm! Mine wobbles around. Although mine is still in good condition, works great,but, just that i feel a bit quite of uncomfortable and uneasy. Is it considered as a 'spoiled' trackpad?
Seriously if you read the how to videos and feel comfortable with replacement go for it. ? Just be sure to have everything necessary including any tools before starting.