Advice on changing bathroom layout in a bungalow with concrete floor.

[dssr]

I’m looking to change the bathroom layout in a bungalow I’ve just purchased from A to B (see pic). I suspect the original layout once resembled B.

 

Will I need to break up all the concrete, or just channel it out to lay the new pipework. If so, how would I reinstate any damp course that I disturb.

 

Finally, the money question. If I don’t feel confident to tackle this stage of the work, what should I expect to be charged to lay pipework and relay/screed(?) the solid floor?

 

Thanks in advance