In FKS perfect hashing we construct two levels of tables. To lookup an element we first check in the first table which points us to the correct second level table that will contain the element if it has been previously inserted. This is always described as static perfect hashing scheme that doesn't support deletions.
However, why can't deletion be implemented simply by just looking up the element and deleting it from the first and second level hash table? You can even completely delete a second level table if you detect that there are no more elements to delete from it.