answer:From just a quick google image search, it looks like they spray concrete over top of pre formed re-bar, so it would make it difficult to do but I imagine a crew with some heavy duty cutters could cut it and rip out a section to make bigger, but it would affect the structural integrity I imagine, and might cause cracking and need for repairs further down the line. Keep in mind I’m no expert, but I imagine that the problems would be a very rare thing, especially since pools aren’t generally in areas with freezing conditions that would cause expansion/contraction. Anyways, to sum it up, It’s probably doable, just ask the company. It will probably be cheaper but you never know what labor will be involved.