Come and discuss anything related to personal finance, directly or indirectly, with other Canadians!
IANAL, but I have worked in development/fundraising. Contested wills are common, and outcomes vary province to province because of local laws.
If everyone is cooperative, in agreement, and works with the executor, then it's not a complicated process. But then that's likely not why you're asking.
It's costly because of lawyers and will drag on for years. A judge will ultimately determine how things get divvied up, or the lawyers will hash out a compromise.
The snag is that the beneficiaries are also executors, and are not on speaking terms due to prior nasty conflicts.
I suspect this will resort to making some lawyers rich, while neither beneficiary wins. The only way to win is for someone to cave in and walk away with something rather than nothing.
That’s probably true.
Another option might be to hire a professional executor. Or an arbitrator.
This is why it’s a bad idea to name all the beneficiaries as executors. (I know this doesn’t help OP.)