BJ, Most of the Gore items we use have access to the area immediately behind the outer fabric - typically a zipper somewhere. However in the absence of same, you would need to simply open an INNER seam to access this area. The outer fabric layer can be breached, but the Gore-Tex ePTFE membrane layer below should not be sewn. Official "Gore-Tex" items are actually subject to an approval process by Gore including seam sealing, etc. Outer seams are sealed - leave them be. But inner seams are usually very easy to open and reclose without any compromise to the ePTFE membrane. Keep in mind that the actually "Gore-Tex" membrane is not the outermost layer, which is typically just a water-resistant fabric, but the ePTFE membrane layer sandwhiched beneath. You also need to remember that when treating the garment, as the outer layer needs to remain breathable in order for the Gore membrane to effectively transport. Always use treatments on the outer fabric that allow the fabric to remain breathable. Otherwise, it's like wearing a garbage bag...