I have seen this a few times. Usually with synthetic forends.
All you have to do is remove the barrel and slide the bolt and forend off the receiver. The Remington directions in the manuel show you how to do this. The bolt assembly can then be removed from the forend. Usually the forend is rubbing at the rear where the barrel is the thickest. You can remove some of the material carefully with a exacto knife or a Dremell tool.
Before you begin this process try to see where the forend is hitting. Also make sure the forend is centered on the forend action assembly. Sometimes when they are installed they will twist and rub on the barrel.