Obtaining a letter of Testamentary for transfer of stocks

What is the name of your state? California
My grandmother recently passed away and left me some stocks in her will she did not have much and as far as I know no Probate hearings were held in the county where she passed. However to transfer the stocks to my name I need a letter of testamentary from the court to have them transfered, how do I go about getting this done? Do I need it from the county where she passed?

Are the stocks worth less than 100k? If so, you may be able to give an affidavit under Probate Code Section 13101. I participated in an extensive thread about this a few months ago. If not, this means a probate. Letters are your written authority to act as the personal representative in a probate. The county in which she lived (which may not be the same county in which she passed) usually has venue.