I'm in the process of servicing my 2020 Kx033-4 (a used machine with 1600 hrs.) and I don't have any service records yet, but still working on getting them. I'll be attempting to change the final drive oil next, and saw in some instructional videos that the drain plugs can be tricky to remove without stripping the 8mm allen inserts in the plugs. It was said that stripping them would be an expensive error. I've ordered a set of impact rated allen wrenches as advised, and will try to ease them out hopefully. Any advice from excavator owners will be most appreciated. Local dealer told me they are $45 each. A less expensive source for these would be nice if possible and if needed. This kind of stuff can be scary!