Newbie with deceased Bitcoin?

Hi, I recently lost my brother very unexpectedly and he did not have a will. I will start this with, I know not to answer any DMs or share any info based on what I’ve read so far! I am the legal administrator of his estate, but my lawyer is not familiar with BTC and neither am I. I do not have access to my brother’s computer or phone. They are both password locked and I am not able to break into them, so that is not an option. What I do have is a list of words he gave me. I was able to open a Blue Wallet with these words and I can see the amount of BTC he had. My question is what do I do in order to actually take ownership of the BTC and/or cash it out so I can put it in the estate account? It is my understanding that this Blue Wallet is just for watching. Beyond that I am totally lost. Any and all help would be greatly appreciated! Please ELI5, I really have zero background on how this works.