AP1, AS1 and ID1 and ID3 and any requirement to send deeds?

My brother and I are joint executors of my dad's will. We have probate, and I want to update the land registry without using a conveyancer. Regarding the change, my brother and I are the only beneficiaries, and we plan to hold the house as 50:50 tenants in common. I have specified this in form AS1.
 

1. In form AP1, can I be named as the sole applicant (question 6 in form AP1) to make the change to the land registry, or do both my brother need to be listed (as we are joint executors)?
2. If it is possible for me to be named as the sole applicant in question 6 of form AP1, do I still need to provide a form ID1 for my brother?
3. If a form ID1 is required for my brother, can this be substituted with a form ID3 instead?

Re the deeds; A title number is held by the land registry for the property. Can I check if there is any additional requirement to send certified copies of the deeds?

Clifford - panel 6 of form AP1 should be completed to refer to the 'new' names to appear on the register, so that would be the two of you as the new legal owners.
You will both need to have your identities verified using form ID1/conveyancer or ID3/others as listed and one for each of you