I have installed those kits when the transmission is still in the car. It can be done. You must have patience with the check balls. As far as the fluid. I have never completely gone with type F. I only add 4 quarts. The rest is dex. You can also use trick shift. Personally I have never noticed any difference between trick shift and using type f. I am sure there is a difference in the amount of friction material but I was never able to feel any shifting difference between the two. I have also installed the kits and used straight dex and never had any problems. I have run into one trans that gained no improvement after installing the kit. The kit worked and the plates did clamp faster but their wasn’t enough grab left on them to matter. This is how I would recommend doing yours. First drain and remove pan. If you can find an old garbage can lid and drills some holes in the center, these work very nice used as a Catch pan when placed on top of an oil drain pan. Let it drain overnight. This will insure that the transmission is cold. Using Vaseline to hold the check balls in place does not work unless the tran is completely cold. It will also allow it to drain more, so that you are not getting frustrated with fluid dripping on you. Once you have cracked all the body bolts. Just lower them enough to allow it to drain further. Oh yea, I also like to lay or line the catch pan with shop towels. I do this to make the ball and bolts easier to see and it insures that nothing drops through the drain holes. I do like to add an adjustable mod to fine tune but I have also done them without adding and they work fine. Drain plugs do make life a whole lot easier when having to go into the pan. I also use a lot of brake cleaner, especially after the valve body is down. I use it to clean everything and help slow down the dripping. I am sure someone will argue with my ways but I am just telling you how I do it and it has always worked well for me.