To inject a morph, you go to Library/Poses, and find whatever it is you want to inject IE: Expressions. Open the folder and locate the expression you want. I don't use V3 without character addons, but I believe if you are using the V3 expressions, that after you inject say an open smile, you have to manipulate the figure manually to get that open smile. It doesn't automatically appear... at least it didn't for me. To inject a character addon, go to Library/Poses and find the character you want to use, click the single check mark and the morphs will be injected. To remove it again, just do the same thing with the corresponding "REM" file. I believe the combo package does the same as the individual ones. It's just a different package.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi