I changed all my 1923 iron pipes. I just finished last month. You need to start little by little. Connect with the rubber connections till you get it all out. I started the PVC at the meter to the main connect in the outside of the house then slowly started doing all the water lines and the main large pipe to the septic tank which was the harder one because of all the digging. Then I did the two bathrooms with CPVC. Just finished. Now will do a new water heater this month.
No more iron or copper.