How do you remove the ability to dial operator assistance

are you using BARS?

i'm not entirely sure, what do i need to do to check on that?

Go to ld 20 and prt a dnb on the digit 9

"0" is found in LD90. It is called an "SPN" or Special Number. The way is it processed is the value of the "RLI"

The RLI is configured and printed in LD86. It defines the trunk routes and restrictions.

Many numbers like SPNs or area codes can use one RLI. So you cant assume changing the RLI wont affect other calls.

Other SPNs you can have that start with zero are 00, 011, 01 thru 09,

To delete "0" you need to consider other calls like International 011.

I say you will ultimately have 0 but it will be restricted to everyone but the ones who overrule you.

But to proceed, add 011 and then remove 0 in LD90. O11 should be routed like other long distance calls but have a seperate RLI that is more restricted.