Estate, Probate, and Debt Claims

State: Colorado

My dad passed away in March of this year and I've been living that Probate life since then. My brother and I are the "heirs" of his estate but uh, my dad was not a planner. No will in place and no beneficiaries declared for most of his assets. My brother and I are totally aligned on things, thankfully, but I'm handling the brunt of the Estate administration since he's got five youngins and well, I have grad school.

Anyway, I am the Estate Representative and have full responsibilities and the fancy court signatures and all that. I'm wondering what my options are for disputing debt claims that may come in - what experiences have y'all had in trying to mitigate what get's paid out of the estate? His estate is pretty small but the catch is that there's a house that's considered an asset for him. He lived with my brother and their family for the past 8+ years, and somewhere along the way they got the house (which was my brother's originally) put into my dad's name because my dad was a veteran and was able to qualify for a super low mortgage rate.

Now I'm finding out he had over $60K in debts (credit, personal loans, etc.) that are all unsecured, but I'm being advised that I can't outright dispute them. So I'm here to ask the world and crowd source ideas - what are my options here? Aside from the house, the total value of his estate is going to be *maybe* $80k, but that's before anything needs to be taken out to go back toward the estate (like the funeral costs, house upkeep, legal fees, etc.)

**TLDR: My dad passed away with a lot of debt and not a lot of assets, what are my options to dispute/negotiate down as much of the debt as possible so his estate isn't totally pillaged?**