Rotating toilet soil pipe exit to other direction

[JimExtension]

We’re thinking of having the door to our extension in the blue shaded area - which passes through the existing SVP.

How easy is it to rotate the exit pipes for the two toilets to go the other direction to join to a relocated SVP (proposed pipes shown in red).

Could this work all be done externally, or is it likely that the toilets would have to be taken out, and then put back in with the new pipe work?

Thank you!

 

[23vc]

Impressive array of various pipes there. Easy, and doesn’t need any toilets taking out. But being able to access and check the back of the pans for leaks afterwards would be good.

 

[23vc]

… although probably need to chip the render and brick away on the other side to accommodate the bend, as the bend tends to start before it’s fully exited the wall. And make good where it was previously