He left £60,000 in an account, and now it’s stuck there because they won’t engage with me over the administration of the estate

My father died with a Barclays account balance of over £60,000. My sibling and I were joint executors. The money in the estate was to be divided equally between us and the rest of our siblings.

Unfortunately, the relationship between my sibling and me has broken down and they are not engaging with me, or the administration of the estate.