Removing tub spout and drain

I am trying to replace old tub spout and drain in a one piece fiberglass tub and shower unit. When I try to unscrew the old Delta spout with a wrench it is obvious it will take a lot of force to turn it. I fear breaking something in the wall and/or the spout itself if I really force it. Any ideas?
Secondly, what sort of tool does one use to remove the drain from the same unit? Should I just call a plumber for these problems???

Some spouts are held on with a set screw - don't know about yours. Did you check underneath it for one?

Jim's right. Some spouts have an allen head set screw on the underside. Some you just unscrew like a big nut. As a personal preference, I like the slip on spouts with the set screw. Makes for easier install initially and removal later on. As far as the drain goes, there is a tool we call a "dumbell" around here. It slips inside the drain and locks on allowing the user to either insert a screwdriver through it to turn or use a 10 or 12" adjustable wrench for turning. You can find these at most plumbing supply houses. Not sure about the big box stores. Getting the new drain started in the drain shoe can be a booger so be patient so as not to strip the threads. Strip them and you'll be kicking yourself in the tail. When you change out the drain assembly you might want to change out the gaskets between the drain shoe and the tub also (on the underside of the tub).

Good luck

spout

If the spout is screwed on, then if it breaks for you, it would probably also break if a plumber tried to remove it.