Shortening the Authors list using et al in ACM Latex

Edit the .bst file and replace the following section of the code

FUNCTION {format.names}

nameptr #1 >
        {
          nameptr #A
          #1 + =
          numnames #B
          > and
            { "others" 't :=
              #1 'namesleft := }
            'skip$
          if$

And replace A with the number of authors that you want to displace

and B with the max number of authors that this snipet won't be applied.