Frustrated, sorry for your loss.
Are you sure you need to probate this estate?
If your dad didn't own real estate, and if his bank will release his funds to the trustees without probate, then you shouldn't need to apply ~a notarial copy of his will and a release/indemnification in favour of the bank, signed by the trustees, might very well satisfy the bank [particularly if the 2 trustees are the 2 beneficiaries].
If he did have real estate/investments that require probate, I've found in our region the turn around time is about 2-3 weeks following application (but that timing varies by region).
Once probate is granted, the trustees can cash/draw the funds from all sources and make an initial distribution to the beneficiaries.
You'll prepare a proposed distribution statement that lists the expenses/assets of the estate [which will include trustee compensation if you decide to take it], and have each beneficiary approve the statement in writing, and provide a preliminary release in favour of the trustees, before any funds are distributed.
From the initial distribution, you should holdback (and this holdback would be set out in the above distribution statement): your estimate of any taxes payable by your late dad/his estate; any legal fees/accounting fees payable to wrap it up.
You'll need to file a T1 return (for the year of death), and then a T3 return (tho I think a T3 is required only if the estate has earned more than $500, but that figure might have changed = if the estate has earned less than $500 than I believe a beneficiary can claim that smaller income on his/her personal return).
Once you receive the NoA, you can apply for the clearance certificate and once you have that certificate, you complete your final distribution statement, send it out to beneficiaries again for their final approval and request final releases in favour of the trustees.
If you can ascertain if probate is not required, you can pm me and I can send you a draft form of distribution statement/ releases. If this is a smaller estate, it should be fairly simple for you and your brother to handle without a lawyer involved.