Removing Existing Plumbing

[Ben C.]

Hello,

I am in the demo stage (prepping to remove all existing plumbing lines). 

Plumber has informed me that I can simply shut off the main water valve in the basement  and then proceed to remove all existing piping inside the home. He stated that he was being honest and didn't want to charge me to come and do this himself. 

Is this correct? Just want to make sure. 

Thank you!