Swimming pools blog

Hi folks,
I have a Pentair SAm Spectrum Amerilite pool light in my inground
vinyl pool. It took on water over the winter, and no longer changes
colors. My local pool company wants about $1000 to replace the unit.
However, I can find a new on online for about $450.
I’d like to do the replacement by myself, but I cannot find specific
installation instructions. I did find the PDF on the Pentair site that
gives general guidelins, but nothing specific. So, here are my questions:
1. Do I need to lower the water below the light?
2. Do I need to seal the back of the light housing where the cable
goes through (it currently is, but I don’t see the need to do that).
3. What is the best way to get the new cable through the 50′ or so of
PVC tubing up to the junction box? I’m assuming somehow using the
existing cable to pull a string through when I pull it out, and then
using the string to help pull the new cable through?

Is there anything else I’m missing?
Thanks…
/greg