@Gordon Nichols posted:
If they are not there, then it's relatively easy to cut them out, using a Dremel tool and a 3/16" rotary hasp.
Important to note to anyone doing this: Make sure you use an honest to goodness N95* mask or, better yet, a true ANSI-approved respirator to do this. Inhaling glass fiber is extremely harmful to your lungs. AFAIK, it’s not a carcinogen like Asbestos, but like asbestos once it gets in your lungs it stays there.
After I watched the safety films at school, I wear an N95 mask even when I drill fiberglass.
*There are numerous YouTube videos about how to insure your mask is fitted properly and doing what it’s supposed to do. Pointless to wear one if it’s not fitted and properly sealed.