1.) If the view of the GB is that elders' consciences should move them to report, then they should explicitly give guidance to elders saying that. Write it down, no weasel wording, but a direct message to elders: "Your personal conscience is very important. Use it regardless of whether or not the law specifically obliges you to try and protect children. You are responsible before Jehovah for your own actions and inaction. Take advice from those qualified to give it on child protection issues, which the service desk is not, and act accordingly."
2.) A formal and fully documented procedure for elders to follow when child abuse is reported to them should be written for each different jurisdiction which takes into account both local law but, more importantly, that this is about protecting children as the priority. The 'sin' aspect of things comes after that. A long way after that.
3.) Involve recognised outside child protection experts in creating a curriculum and training course for elders. Allow them to provide it at elders' schools. This will help to raise awareness as well as give elders outside perspective of the issues involved and the need to pass things to people who can help appropriately. Regularly seek updated perspectives from child protection professionals on amendments to policies - review of what is effective and what isn't is important.
4.) Acknowledgement of there being an issue publicly. Openly admit the problems being faced and what is being done to solve them. No weasel wording. No passing the buck. An acceptance that they are a hierarchical religion and a willingness to accept they have a duty of care, sometimes legally but most definitely morally. An apology to those they've failed and public statement of what steps they are now going to be taking to try and ensure it doesn't happen again.
Sorry I can't be more practical with suggestions, and it's sad that even those will have little chance of being approved by Brooklyn. If someone keeps closing the curtains on the inside, it's hard to get sunlight from the outside.