But why would you sell a property that is performing well?

Its much harder to turn a property around in 6 months expecting to have 100% of your money returned back to you - but if you focus on the right property focusing on highest and best use with an ADU add (like mentioned), in-fill/lot split, or other rehabs - then hopefully a semi-decent property like that will perform like a champ in a few years. 

As a beginner, I would personally get my feet wet with something a little less risky without a balloon payment like that.

What due diligence is performed to make sure a market will support their co-living concept and what percent of the rental market?

Personal Guarantee: Will you require this?

I have about $300k in equity (based on a BPO performed in July 2023) but no cash.

Personally, I would keep the property but I don't know your situation and if you could better use the money elsewhere.

Get with a few contractors and have them different quotes and how they will perform the work.

I specialize in small multifamily properties and house hacking working alongside BiggerPockets podcast guest Andrew Freed to help investors find high-performing deals in Central MA.My Background:  - Started in late 2019 I utilized an FHA loan to get my first 3 family property in Fitchburg, spent about a year fixing it up and soon after I refinanced. 

While I certainly think that reducing retirement account contributions and investing in real estate could be a great option for an early retirement, it requires honest conversations and detailed projections around your current portfolio's performance and expected rate of return on future acquisitions.