If probate has not yet been granted, you can file a notice of objection to probate. This prevents the will from being executed until your objections are resolved. If probate has already been granted, you must start a court action to challenge the will.
You will need to gather evidence to support your claim. This can include medical records that show the testator lacked mental capacity, witness testimonies about undue influence, or documentation proving improper execution or fraud.
The court will review the evidence and decide whether the will is valid. If the court finds in your favor, the will or specific provisions may be invalidated.