If it's the old style cellulose, it's not worth the space it occupies. As Bryce indicates, it settles, compresses, breaks down and sustains mold growth. I once asked an energy efficiency expert to calculate the R-value of 12" of 30yr. old cellulose and he informed me that he could not provide the information due to settling, compression and age (today's cellulose is much more effective).
The only thing that pops into my twisted mind is to use a leaf/vac/mulch unit but, hook up the hard tube to the discharge and maybe rig up some flexible duct to extend the discharge to a containment unit of some sort. If all goes right, you should be able to remove it almost as quick as it was installed.