Of course, you should have some grenades or molotovs. Open up your Pop-Boy menu and head into the weapons inventory.So we are here to walk you through every step of the process and you’ll be throwing grenades all day long Step by Step Instructions to Throwing Grenades in Fallout 4 It is not part of any in-game tutorials, and the mechanics are a bit different than the other installments of the saga. While throwing a grenade is not exactly rocket science, there are some tricks that may help you take your gaming to the next level. It’s not everyday that you have to turn to the internet to find out how you throw grenades in an FPS, however Fallout 4 does not entirely fall into this category.