Swimming Pool Light Assembly
 

The old light assembly in our pool had water get inside and was tripping the GFCI breaker. I purchased a new light nich assembly and all I had to do was pull the old light cable out of the 3/4 inch conduit. I thought it would be an easy pull so I jump in the pool and give it a tug and then everything I had and it would not budge......6 hours of tugging from under the water was enough.
So I had to rethink this. I snip the wires off and put the end in me cordless drill thinking the twisting force might make it break loose. Well the drill worked and it was actually easy to change it out. O.K. Some credit actually goes to my wife.

Usually that cord needs to be loose enough to allow that light to be put up on the deck up here in the north, when winterizing a pool. Our cord just wraps around the back cone of the light a couple times when mounting it back in the receptacle.

Using a drill to loosen the old cord is a good idea.

When we used to do them we would use two guys, one on each end and do a push-pull to free it. Once free the old cord can be used to pull the new light cord from the pool side to the J box. Make sure and get this right with all cords, connections, and fixture water tight. Every year a dozen people are killed due to a faulty pool light repair.

Never run power to the light on deck. They get hot super quick and kill all the seals.