I want to do a few basic mods to my srp777

1) Coin Edge Bezel
2) Ceramic Bezel Insert
3) Sapphire Crystal
4) Replace the second hand with one with the lume Lolipop @ the other end of the second hand.
5) Add a signed Crown.

I have basic tools and have done a few things before, but I am no watchmaker. I have figured out a few things, but there has to be some good tutorials out there. I searched and I am not exactly finding what I am looking for. I have actually done everything before, except not on this particular watch so things look a bit different. I have opened up the watch and removed the crown/stem and have the bezel & bezel insert off.

1) Do I need to let down the mainspring? If yes, then how do I do that on this movement. I watched a couple videos, but they were not for 4R36 and when I tried what looked to be right it didn't seem to work. I do realize I could just let the watch wind down, but that would take a little bit of thinking ahead and I don't do that very well....

2) It looks like there is a retaining ring holding the movement in place. How do I remove that so I can remove the movement?

I guess maybe someone could describe how to do these two things I might be able to muddle through, but I'm thinking I must be looking in the wrong places as there have to be some good tutorial videos specifically for Turtles

Thanks