Package errors while migrating from Gatling 2 to Gatling 3


I am in the process of migrating my scala load test scripts from Gatling 2 to Gatling 3. I am using AWS Linux machine to do this process.
I downloaded Gatling 3 in AWS machine and copied my data and simulations to Gatling 3.
While executing the simulations i am getting so many package errors as below…

object ExtraInfo is not a member of package io.gatling.http.request
import io.gatling.http.request.ExtraInfo

object asynchttpclient is not a member of package org
import org.asynchttpclient.util.Base64

Can some one help me to resolve this issue?

Thanks in advance,
Swetha. G

Below packages are dropped in Gatling 3.0. Check Gatling migration guide: