so are you suggesting not bothering to replace it? I don't do any intentional off roading but there does seem to be alot of crap that's collected in it!!
Instead of going through the trouble of removing parts to get it off, if you jack the vehicle at the point where the front arm bolts to the chassis, it will raise the engine away from the axle giving you more clearance to pull the undertray out, you may have to give it a few yanks but its bound to be covered in oil etc so will slide out without having to remove any other parts !!!