I've removed the actual motor block, magnet, from a XF280. I have not on the new XF3xx series. If you do a search on Google or whatever you prefer there are some videos on it being done.
That being said they typically do not need that level of cleaning even if aged. Just grab a 4 gallon bucket or something along those lines, add in some citric acid, hot to warm tap water, and take the gyre apart and place everything in the bucket. Let is soak for a few hours. Then remove each blade, cage, and holder and gently brush off whatever is left. Rinse, reassemble, and you should be good.
This was my routine. In fact since Maxspect typically ships with spare blades and cages I more or less stopped the gyre, removed from the tank to rest on euro brace, disassembled, reassembled with spare parts (clean), then put back in tank, and turn on. Less than 5 minute task. Take dirty parts and go through the soaking process then put back on shelf for next rotation.
If for some reason you feel the actual motor block is super dirty just soak it as the norm and then turn it on to run for a bit. That will loosen up build up, rinse, and be done.
If you really want to deep clean then search to find how to remove. I recall on my 280's using a pair of needle nose pliers to grab and pull out. I would suggest reaching out to Maxspect and get their advise on how to properly remove if so.