I don't believe you can proceed without counsel. This is a very complicated situation. To refute a will requires evidence and a hearing. Those that absconded may be prosecuted criminally as well as sued in civil court. You may be able to do this based on the facts presented but you need a local attorney to advise you. Good luck!
Please be advised that the foregoing discussion is a generalized and hypothetical answer based upon incomplete facts and is not intended to serve as legal advice to you, nor should you regard it as an attorney-client communication or as creating an attorney-client relationship. If you desire legal advice concerning the situation you have described you should contact an attorney who has substantive experience in the fields pertaining to your question.