Hello everyone I'm replacing my lt1 valve stem seals I got the plastic tool to install them Ihor far down do I put them I just use my hand force then it stop can't go any lower am I supost to hamer them down or is that where they should be where they stop any input apreciated thanks

 

you can see how far they go down by looking at the original ones. sometimes a "light" tap with a small hammer using a socket that is just the size of the edge of the seal if you can't "push" them all the way down by hand