Find a new shop. When a mechanic says "it could be..." when it comes to leaks, it's time to move on.
As far as removing the rack, there's two lines going to it and it's held on by two bolts. Usually you can pop both tie rod ends out and then slide the entire rack out the side of the car. I think in the Accord's case it just drops down... either way I wouldn't expect to pay more than 3-4 hrs labor for a R&R job. Does the mechanic even know what is leaking or is he just going to sell you a new rack, pressure and return lines?