1. Add the residuals to L3. There are two ways to add the residuals to a list.
1.1. Method 1:
Go to the main screen. [2nd] "list" [ENTER]. Scroll down and select RESID. [Enter]. [STO->] [2nd] "list". Select "3: L3" [ENTER].
1.2. Method 2:
Go to [Stat] "1: Edit". Select L3 with the arrow keys. [Enter] [2nd] "list". Scroll down and select RESID. [Enter] [Enter] again.
2. Turn off "Y1" in your functions list. Click on the = sign. Press [ENTER]. Press [ENTER] again to get it back.
3. Go to Stat PLots to change the lists in Plot1.
Change the Ylist to L3.