It's very important that you hire an attorney for this probate as it is very difficult to get it through the court without an attorney. There is a very specific probate procedure in order to sell the property and it must get court approval.
You cannot sign the decedent's name and you cannot sell the property using your 'letters of administration'.
This answer does not mean that there is an attorney client relationship and is not meant as legal advice. For legal advice you would need to call us.