They're currently renting in Denver under only the guy's name but since the girlfriend is pregnant, they need to move to a bigger place.

@Ellis Moyewe really don't know a lot about this situation since there aren't many details in your post... but i don't think this makes any sense for anyone involved here...if it's a flip that's not selling, refinancing may not solve your problem and allow you to pay back the HML in fulland typically a sub to buyer wants a low interest rate... and if you refinance now you won't be getting a low interest rate, you'll just be getting whatever the market offers.and finally.... the vast majority of loans are NOT assumable. 

As others have mentioned, you typically need some liquid capital to get a deal done even if a hard money lender was funding 100% of the deal for you. 

Quote from @Anshuman Thakur: Can someone please shed some light on how- convert 401k to SD IRA- how to use SDIRA to buy properties- how much down payment is typically required if we are using SDiRA to only fund downpayment on a multifamily CRE, and which banks typically work with SDIRAs- how does LLC structure- property management and cash flow work in this situation?

Quote from @Clayton Silva: Quote from @Jeffrey Blackman: Quote from @Clayton Silva: 2nd position HELOCS on investment properties are typically capped at 70% LTV and have rates ranging from 9-11% just a heads up unless you use a local credit union where you have cash on deposit with them. 

Typical Project Management Fee for a GC General contractors (GCs) typically charge a project management (PM) fee of 10-20% of the total project cost.

You typically will see small banks/credit unions probably wouldn't be able to out-of-state, but otherwise any mid-size company or larger should be able to.

@David LewisRecommend you first figure out the property Class you want to invest in, THEN figure out the corresponding location to invest in.Property Class will typically dictate the Class of tenant you get, which greatly IMPACTS rental income stability and property maintenance/damage by tenants.If you apply Class A assumptions to a Class B or C purchase, your expectations won’t be met and it may be a financial disaster.If you buy/renovate a property in Class D area to Class A standards, what quality of tenant will you get?

Recommend you first figure out the property Class you want to invest in, THEN figure out the corresponding location to invest in.Property Class will typically dictate the Class of tenant you get, which greatly IMPACTS rental income stability and property maintenance/damage by tenants.If you apply Class A assumptions to a Class B or C purchase, your expectations won’t be met and it may be a financial disaster.If you buy/renovate a property in Class D area to Class A standards, what quality of tenant will you get?

@Austin Tessyes, you can get a loan to do a flip, but flipping still requires your own cash - it's typically impossible for a brand new investor to borrow an amount that covers all of the costs of a flip.