Our toilet is cracking and needs to be replaced. What concerns me is that the bolts which hold it to the floor (concrete slab) are severely rusted and don't even hold the toilet firmly anymore.

How much trouble is it going to be to have it replaced? Will they need to tear up the concrete to put in new bolts?

Bolts should be fitted to the toilet flange not the concrete floor. They should also be brass. Brass does not rust. Nuts may be steel and they might rust. Use 6 point socket or box in wrench to remove.

Unfortunately many of the new ones are brass plated. Just saw off the nuts and get a brass set.

Thanks! That's a relief, I thought they were embedded in the slab. These bolts are definitely not brass though, and are thoroughly rusted.

Another question... the new toilet will obviously have to be a "low flush" type. What's a good brand with a strong flush? I don't want something that has to be flushed 2-3 times to get everything down.

Oh, one more thing... I won't be doing this work myself. Would I save any money if I bought the toilet, and had it installed, versus letting the plumber supply the toilet?

If you go to HD or Lowe's, they have toilet ratings by flush power. I like a Cadet 3. Not to take business away from professional plumbers but if the floor is OK and the flange unbroken, or even broken for that matter, basic floor mounted toilets are pretty much a DIY project today, all parts in 1 box. Set the bowl over a new wax ring, bolt it down, bolt the tank on, connect the water pipe and flush away.

Just remember a 6 point socket or box in wrench (assuming a hex nut) to remove. If you want or have to cut the bolts, use a sawsall with 9" metal cutting blade. If you want an excuse to buy a new tool, get a multifunction saw from Harbor Freight. Cost about $30. Forget Harbor Freight blades. Get a package of Imperial blades, also about $30. You will find many more uses for it. I agree setting a toilet is a DIY job for a reasonable skilled handyman. I like Toto.

Thanks but I really prefer to have this done professionally.