I was the Resident Engineer on the demolition of the Arkansas Titan II missile silos in the mid - late 80s. Well,most of them anyway - one was pre - demoed in the 70s when a worker in the silo dropped a big wrench socket that punctured the fuel tank, resulting shortly later in the missile blowing up, blew the blast doors off the silo and launched the unarmed nuclear warhead into a mortar-like trajectory into the darkness. It took the Air Force several nervous hours to find it. So we didn’t have much demo to perform on that one.
On the others the AF removed the missiles and I think they went to places like Vandenberg AFB to be used for various Satellite launches, etc. Our contractor cut up the blast doors (12 in thick steel from memory) with huge gas torches, drilled and shot the massive concrete headworks up, excavated the top of the silo and concrete rubble to a big cone, waited some period of time for Soviet satellites to photo and verify according to treaty, demoed the entrances/stairwell to the underground control center, pushed concrete rubble and other fill into the silo below until back flush with ground, and then the land was returned to the prior owner or otherwise sold. Arkansas did not retain one of the silos as AZ did which I think was short sighted. Interesting project.