Switching hard money loan after 3 months

[Andrés Uribe]

Hello BP community.

I need advice on how to approach a hard money lender about switching my loan, from what I was already approved for. I've had the loan for 3 months now, and I might need to switch my strategy since my current contractor is very much behind (2 months) his timeline. This would have been for 2 simultaneous rehabs of two homes. I have a loan for the purchase and the rehab. 

Since I might have to let him go, I am having a hard time finding replacement contractors, and I am now speaking with a modular home builder about tearing it all down and building 3 modular row houses. So...

Current loan is of $500,000 with appraised value of $820,000.

New loan would be $1,179,000 with potential of $1,788,000.

Has anyone had to switch a loan before, if so what would I need to take into consideration? How did you make it work? How were you not able to make it work?

 I have a spreadsheet detailing new costs, current loan, and new construction comps in the neighborhood my properties are in, sold in the past 3 months, new construction, and within a .5 mi radius.
thank you for reading and your time, it is greatly appreciated! And a very Happy New Year!

Andres