Removing a stuck light

[DIYFlorida]

Hi I’m hoping to get some advice on removing a light fixture from a 1970’s pool to replace it (I think that’s it’s age). Tried pulling it out and it wouldn’t budge. Boyfriend wrapped a 2x4 around it and tried to pry it out- wouldn’t budge and wires snapped with only about a foot to spare in the niche. The only thing I can think of at this point is cutting the concrete deck behind the niche and replacing the conduit (it’s currently in about a 1” pvc pipe- surely that’s not code anymore). Don’t intend to do the final wiring myself-electricity and water freak me out a bit, but was hoping to do the setup myself and save some money. Any advice? Is my idea about cutting the deck a bad one? Thanks in advance.