Has anyone taken out R410 from a R410 system and put in R22.

No. I wouldn't even think to try. Will be impossible by design of the 2 systems.

I have seen that only once, where a hvac tech didn't read the ID plate to charge a leaking system that had leaked all of the R410a out, and recharged it by ACCIDENT with R-22. It did NOT work after the recharge!!

Sort of expensive but can be done. You need to change the compressor and metering device

sort of expensive but can be done. You need to change the compressor and metering device

You need to flush all the POE oils and add mineral oil. You will have a flooded condenser coil. Since 410A has more BTU per lb. than r-22, the condenser coil is smaller. And on and on and on. You may as well make your own A/C system.