A seal-cover assembly for a structure including a first side and a second side opposing the first side. The seal-cover assembly includes a cap defining a recess, and an insert fixed to the cap within the recess to form a cover unit. The cover unit is configured to be secured to the first side of the structure. The seal-cover assembly includes a fastener configured to be disposed through the structure from the second side of the structure. The fastener is attached to the cover unit relative to the second side without accessing the first side of the structure. Additionally, an aircraft includes the structure and the seal-cover assembly as discussed above. Furthermore, a method of assembling the seal-cover assembly to the structure includes the cover unit secured to the first side of the structure such that an interior of the cover unit is inaccessible from the first side.