I investigated this for my 251 CE. To remove the “Chart Bag” (made by A & J Canvas of Fayetteville, NC), you need to disconnect the small “slide tracks” from the T-Top. These side tracks are attached by rivets You will need to drill out the rivets and after cleaning re-attach the side track with stainless or aluminum bolts. For the time being, I opted for a deep cleaning in place by covering the helm and seats and some vinegar and simple green.