My DH died 4 years ago after a short terminal illness. Luckily we had joint Bank Account & Savings Account, only his ISA had to be closed, Banks only need to see Death Certificate as they scan it onto their system.
I had already changed all Utility Bills into my name many years before as I dealt with all the finances so no problem there. Car was in his name but he had not driven for many months so I had changed main driver on Insurance to myself (DD has been a named driver for years). I had difficulty persuading my DH to sign V5 to change car ownership, he couldn't see why although he knew he was dying, I explained as Insurance was now in my name car should be, he signed, that did save me hassle with DVLA.
Every Pension etc will require a copy of Death Certificate so have a look & see how many will be required, saves waiting for certs to be returned. Do it once only informs Government Depts, eg State Pension.
I need to update my Will, I have my copy but original is held by Solicitors in Somerset & I now live in Devon, also now I'm widowed & have a new property & another DGS due in May, a Revision is due.
I also intend to do LPAs soon.
Unless Finances are complicated I would not use Solicitors as Executors, they can charge hefty fees which come out of the Estate before you receive any Legacy. If there is Property to be sold they will deal with that also. My DD is my Executrix & we are my DM's, Probate can be dealt with by any-one (I worked for Civil Service).
I keep my up to date papers in an expanding folder so everything is on hand