There is no reading of the will. It only happens in American films.
One of the executors makes an arrangement with the solicitors to go and pick-up the original. Then what you do with it, in terms of reading it amongst the family is entirely up to you.
If the executor has not collected the will and will not give permission for the solicitor to relaese it and none of the assets have been frozen can the other persons concerned ie sisters of the executor engage therir own solicitor to act for them? or do they just have to sit back to let everything happen around them?