The first thing you want to do when trying to replace the forend of your Remington 870 is to make sure the weapon is unloaded. You’ll want to check both the chamber and magazine tube by visually looking at them and by feeling around with your fingers. That way you can ensure that you don’t have any accidents during the process of replacing your forend. Next, you will need to gather the right tool for doing this job. There is a special forend removal tool that you can purchase at most gun stores, but if you have a pair of pliers then they will be fine.