To shove or force something into (a space, box, bag, etc.); to push in with some force.
溢れそうな箱に無理やり荷物を押し入れた。
I forced my luggage into the overflowing box.
彼は重要な書類をバッグに押し入れて店を出た。
He shoved the important documents into his bag and left the shop.
議論に自分の意見を無理に押し入れるのはやめてほしい。
I wish you wouldn't force your opinion into the discussion.