Yes, they were a pain. But I did find out that using an air chisel helped get the stubborn ones out!Drilled them, but it was a major PITA. used quality bits, started small and worked up to slightly larger than 3/16" to get the heads to pop off. Drilled only on the inside of the tunnel. We just took the rear bolts of the skid out and suspended the tunnel overhead via the drop brackets.