Yes, I believe there are several but I can't seem to easily find them now. It's been over a year since I disassembled mine and it's not really that hard. Just be patient, you'll have to remove the top and side cabinet panels plus the main water in and out. It seems most of the circular tube arrangement heaters are the same internally so a video for a similar Pentair or Hayward will be very similar to yours. You don't need to disassemble the fan and other parts on top of the heater box other than the igniter. It's very fragile so I'd remove it first and set it in a safe place. If you tap it lightly on anything it will crack. You will need to remove several wires that connect back to the control board and heater valve to get them out of the way. Just take a photo to be sure you know which goes where to reassemble. Carefully disassemble the gas union. It's easy to accidentally pull the air tube off on the bottom of the fan which causes problems getting the unit running again. Then remove the ring clamp and pick the whole lid off in one piece after you disconnect the gas pipe union. You'll need an insulation kit since the water will destroy most of the insulation pad on the bottom. The new bundle comes with new o-rings. Depending on how deep the water got you may need to clean the burner assembly thoroughly to make sure none of the fine mesh holes are plugged. If you need to do this it may be easier if you just set it back on top of a small trash can. When you get the manifold off take a photo of the tubes and post it here. If they are protruding normally you probably had a mechanical failure and not a chemical balance issue. Most of the videos I watched it was pretty obvious when it's a chemical problem.
Good luck, please post video and photos as you go.
Chris