You need a 3/8th ratchet or breaker bar for leverage. Just make a quick note of the belts routing so you don't fubar the new one.
30k seems early but these new belts don't physically breakdown and crack like the old ones but they do loose their grooves. The belts are cheap (around 30 bucks at most) so it isn't exactly going to break the bank once every 2-3yrs.
Your car's engine drive belts run accessories, including your power steering and air conditioning. They also run the charging system that keeps your battery charged. These drive belts are made of composite materials. They work hard and will stretch, fray, crack and become brittle over time. Eventually they will need to be replaced