IRF (stacking) Configuration on HP Comware switches (5130's)

I currently have a stack of 6 HP 5130's and would like to add another switch to that IRF stack.

I have everything on the same firmware, etc. but I'm confused as to when to enter the configurations on the new stack member switch- before or after cabling everything up?

There's numerous guides online, and they all describe the process as configuring the new member before cabling it up. HOWEVER, in the example configs they show entering the interface configs on the new member switch as interface 7/0/48 - 7/0/50, but until the switch is in the stack, you don't have an interface 7/0/x, it's interface 1/0/x, do you know what I'm saying?

This is an example procedure:

system-view
    irf member 1 renumber 7
    y
    save f
    quit
    reboot
    y
    -STOP----- (after reboot)
    system-view
    interface range  Ten-GigabitEthernet 7/0/49 to Ten-GigabitEthernet 7/0/50
        shutdown
        quit
    irf-port 5/1
        port group interface Ten-GigabitEthernet 7/0/49
        quit
    irf-port 5/2
        port group interface Ten-GigabitEthernet 7/0/50
        quit
    interface range  Ten-GigabitEthernet 7/0/49 to Ten-GigabitEthernet 7/0/50
        undo shutdown
        quit
    save f
    irf-port-configuration active
    save f 
    (The device reboots now automatically)

Finally, add the switch to the stack, power up, and connect IRF-cables

But how can I issue interface commands to interface 7/0/x before the switch is a member of the stack and only has interfaces 1/0/x?

Thank you

Well, I figured it out- Once you assign the IRF member ID (7, in my case) the interfaces change from 1/0/x to 7/0/x.