Hi, I'm currently working on reviving my neighbors go-kart that looks home-made, to me. I want to replace the engine, already got the other parts to easily fix up the other rusted parts. The engine is currently stuck onto the mounting plate, the screws are stuck together and move as one whole when trying to remove the screws, making it hard to remove the engine. What tools besides a wrench and pliers could I use to help me remove the screws? (Hexagonal screws). It's been siting for years.