How were the first microprocessors made?
How were the first microprocessors made? ... can an ordinary guy try to make one?


An ordinary person doesn't have the resources that were available to a business like Intel in 1971. 

It would be like filling your garage with this



And from that constructing this 1971 artifact using a budget of $500 and one person's evenings and weekends.



However, you can construct a CPU from basic logic ICs - Example



See this answer to the Q of which this is pretty much a duplicate.

It took Jeri Ellsworth 2 years to make an inverter (two FETs) about the size of a quarter. Most of that time was working out a process simple enough that she could use it at home. So I guess she could probably go on and eventually produce a logic gate a day using that method. So that would take maybe 10 years (weekends off and a couple of vacations a year) to make enough gates to construct something like an Intel 4004. The result would perhaps be a "chip" the size of a large car (if not a small house).

Some other people are working towards a smaller scale, more integrated, and less hand-hewn process - but it seems they've been working for a couple of years and don't have any working devices yet. They do have some impressive small-scale artifacts though. I'd guess they may still be many years away from process that is both affordable and usable at home.