A Will is a written declaration of a person of things he wishes to take effected after his death or at the time of his death. At the time of his death is when one is in a coma and wishes to end his life peacefully. I am not sure whether this is legal in Malaysia, maybe not.
A Will can be hand written, signed by the one who made the Will and signed by 2 witnesses. Witnesses cannot be the beneficiaries of the Will such as parents, spouse, children or anyone that the person puts as beneficiaries of the Will. Most important, the person must be of sound mind at the time of signing the Will.
Well, you and I can just create a Will without paying anyone to do it for you. Just get 2 witnesses and have it signed. It will be a legal document.
In most cases, people will seek corporation help when he/she wants someone trusted to be the Will executor. The executor is required to carry out the distribution accordingly, seek legal help to apply grant of Probate from High Court and a lot of running around. You are advised to name 2 executors in your Will, just in case the main executor either cannot carry out the duties or he/she passed away. It is not easy to become an executor if the Will is not written properly.
I guess that is one reason why many people seek professional help and willing to pay a fee for it.