Dont use a pvc reducer for the rms. It always see,s to go at an angle.Especially if you have the car on stands and the engine is off angle. A 3 inch to 3 inch pvc connector about 3 inches long works fine.
Like the one in this link:
4 in. Schedule 40 PVC Coupling SxS-429-040 at The Home Depot
Again tap softly and slowly all around. It works well. The contraption you have seems like you are going to shoot a canon!
The reducer seems to push it at an angle. Once it goes in an angle the lip is probably messed up and removing is only that much harder. I damaged mine that way. Had to run to the dealer and two more for good measure. Also dont use sealant. If you are concerned then push the rms in until it is sticking out a couple mm. Then seal the edges all around and tap it in. A new seal when installed well should seal it tight. You will know what i'm talking about when you tap it in. It is one tight seal.
Again take your time and go slow. Do not fight the rms and the ims.
Why are you changing the tensioners? Cant image how all 3 are bad. But do change the o rings and crush washer. Nomsealant here here either.
When bolting down the ims flange do not exceed the torque. Those bolts that come with the kit are made of chalk! Seriously. I ended up reusing mine.
Fr the cv boots. pack the grease in. As much as you can. If tour original cv were torn then clean them up well? I used kerosene to wash thoroughly to remove any sand particles etc. There were some. Good luck.