The double sided tape is just to hold everything in its proper place and not bounce around if/when you move the PS3.
When I get mine in I will probably use a double sided foam tape to hold everything in place (I move mine about 60,000 miles per year in an rv, so it gets a good bump on occasion ). I need all the cushion I can get.
You will still need to do some soldering, but it doesn't look like it will be all that hard to do.
Even if you have to buy the equipment and learn how to solder........it's not hard.
I would not recommend your first shot at soldering being done on the ps3 (maybe an old f-ed up tv, radio, computer mother board, graphics card.........).
That would give you a good idea of the amount of time to keep heat on the contact points and get a good looking solder joint without screwing up a good working piece of equipment.
I would much rather go to my grave not needing my gun, than go there wishing I had it.