Accessing wallets by an executor

I am in my 60’s and am setting up my last will and trust. Does anyone here have experience as an executor or POA obtaining access to a deceased person’s exchange? I know how difficult it can be working with an exchange customer service on our own issues, I am imagining it to be extremely hard as an agent for another’s portfolio. I’ve been through this with stock exchanges and it’s not fun.

Please stick to the question and not go down the self custody road, that’s not the topic here as many of us do trade on magor exchanges.