Yes go to my profile, lower right, read the file Bullet Proof rentals.  

sounds like a good deal if you can pull it offyou would have to do some infrastructure work to make the units pay for there water, plus going to mini slip units would reduce energy from the window unitsraise the rents to what is current for your area and re crunch the numbers plus add the upgrades to see where you are sitting with the cap rateat this point your looking at 30k per unitI'm not sure if this is a good deal in your arealook at improvement costs, reevaluate your upgrade costs and do a comps per unit in your areathis should give you a better idea if you want to continue on the purchaseenjoy

I know we have the will, I know I have the energy and desire to accomplish these goals.

See if you can check out any of the books from your local library, or bite the bullet and buy one or two of them (the education a $20 book will give you can pay for itself a thousand times over).

Also, you can borrow extra money for Energy Improvements, like windows, insulation, hot water heaters, etc. 

If you want to save money, consider trying to work with a Realtor who might negotiate their fees down (though some high quality Realtors will NEVER negotiate fees down).If you truly want to do everything yourself, consider what everything is and if you have time/energy and EXPERTISE to do so. 

Using what you found in Bullets #3 and #4, determine the value. 

In a 4 plex the bill instead of being split 4 ways is only split 2 or if 3 tenants move now only 1 is paying the whole thing and since the building is not sub-metered you can't turn off the main breaker to safe energy.

From a level-of-involvement perspective, what kind of time and energy can I invest?

If not then its up to you to see the cost of taking him to court or just biting the bullet and moving on.