press (something) into (something)
To force someone or something into some space or crevice. The criminal pressed the hostages into a supply closet and locked the door. I pressed the part into the right slot, but the machine still didn't work.
press something into something
and press something in 1. to force something into something, such as a mold. Now, you need to press the clay into the mold carefully. Now, hold the mold with one hand and press in the clay.
2. to force or drive something into the surface of something. You are standing on my chewing gum, and you have pressed it into the carpet! Don't press in the gum by standing on it.