Oh lord that's a mess !
if you look on their web page, they have an 800 number you can call and talk to them directly with questions about how to take care of the unit.
I do not have one of these so can't speak from any kind of experience but if it is glopped up that much. Possibly remove the blower if it's easily mounted and you are a handy person? Other than that, some degreaser sprayed on would probably work.
Just if you use any chemicals or even the potential of having loose stuff that can possibly burn off. Run a 'cleaning batch' through it. ie a load of crap coffee, that way if there are any off flavors due to goop burning off on a heating surface etc, it won't taint the taste of your otherwise good coffee.
If you got crap glued on the squirrel cage fins then removal and degreasing is about the only viable method I can think of off hand.
If you decide not to go the removal route, a hand blower / hair dryer or tile heater set at a very low setting might help too, give it a gentle heating to soften that stuff up then use a brush to get it off the fins.
Can you possibly post some pictures so we can see exactly what you are talking about with it?
Thanks
Aaron
Edit: Here is a link to one of their pages that has some contact info for them in case you decide to call them for further guidance. When it comes to any type of disassembly they are probably your best source of 'how to'.
https://sonofresco.com/tips-for-better-roasting-using-your-sonofresco-coffee-roaster/