1. Dear *****, essentially, you need to issue a Contentious Probate Summons in the County Court to seek to have the monies paid over to your son. You can get a copy of a precedent for this in the Green book, which is the County Court guide for barristers or alternatively, you can get a copy of it in Sunnucks & Mortimer on Probate, which is a well known legal text. Alternatively, you can get a solicitor to help you and do the case for you.
2. However, before you rush to issue legal proceedings, you should get yourself a copy of the will and examine its terms. This is because very many wills contain a clause which permits the executor to retain a bequest under a will until the beneficiary reaches 18 years of age. So, you should first ascertain what are the terms of the will as to the holding of bequests for minors. As your son may be less than 18 years, he may not become entitled to his bequest under the will until he is 18. Here, you should speak to the solicitor who is acting for the estate (or to your brother) if you have difficulties with your brother.
3. Please Accept or Rate the answer as unless you do so, your Expert will not receive payment for answering your question.
4. The name of the form is a Contentious Probate Summons. Secondly, you can get an order for costs against your brother once you win your legal action against him. However, this does not entitle you to place a hold on his house, unless he fails or refuses to pay the legal costs. If he doesn't pay the legal costs you can then place them as a charge upon his house. However, this only occurs if he defaults in payment.