Some regs are easier to work on then others either because of number of internal parts, special tools, or subtleties of design which make it difficult to determine the disassembly points and methods. This makes it necessary to have diagrams and obtain some practical tips or shortcuts. Once the owner acquires the few basic tools and one or two special tools, he needs the parts kit. So, the main effort is not the overhaul per se, it is getting ready.
Although the average mechanic does not have the experience of a pro, he isn't usually under any kind of time constraint. If it takes twice as long, so what? He is motivated to do it right, and can do so under his own time schedule. He can afford time and effort to clear a work area, lay out a clean cloth and spread out the parts in logical order. Moreover, he probably won't have to do this every year. Once he gains knowledge from doing, the amateur will be better able to judge whether there is an actual need to overhaul these well made and durable devices every year as opposed to a more extended schedule. He may decide that the fewer overhauls the better, no matter who does it.
The amateur will not need all the special tools recommended for the pros. However, he will need to cobble up an IP test gauge with a 3/8" fitting. He may need a special spanner to open the regulator first stg. A dental pick is often useful. He may need a C clip pliers. He will need some special lube. Special gauges like those which are used to check inhalation effort or cracking pressure are probably not needed. The amateur can "wing it" with a bit of insight, and trial and error on the bench. However, if special tools are preferred they can usually be obtained. Be aware that regs are made of soft materials. If clamping is necessary, use a tool or vise with soft jaws and use minimal pressure in the right spot. If something is not right, stop and review everything. Ask someone.
Each reg has some little tricks to make the job easier and avoid damaging something. For example, SP recommends a special inline tool to adjust the orifice (fine tune) on some 2nd stgs. However, a screwdriver will work well, at least on the older models. The manual also says that the poppet has to be removed first to prevent the seat from being cut by the orifice which is being rotated. However, merely depressing the diaphragm while rotating the orifice works just as good, e.g. doesn't damage the poppet's rubber seat while adjusting.
In summary, there are usually several shortcuts or work arounds which will get you home and the result will be just as good as the pro. Learn about your reg, get the tools and parts, and be confident. You are only responsible for one or two regs, not a couple hundred.