On the exterior, new roof and freshen up the roof.  

New roof, exterior paint, laminate, and carpet.

Otherwise you should wait till they move out, or only post exterior pictures for now.

The best you can do is try to estimate interior needs based on exterior condition.

In some senses there's usually less supply, but at the same time, there's less demand because the 'recreational' investors who get through one project / year don't mess with stuff during that time.Some projects are nearly impossible to do around here during winter, like most exterior, concrete, roofs, etc. 

Value was added to this property by remodeling and upgrading the kitchen, bathroom, flooring, fixtures, interior/exterior paint, plumbing, garage door.

I own a small 6-Plex in Tacoma and would like to replace all windows & exterior doors in the near future.2 doors per unit = 12 Exterior Doors3 Windows per Unit = 18 Windows.Does anyone have a recommendation on how to get this done in an effectively and economically?

From my perspective, they FAILED to maintain the exterior (which they cover per the CC&R) and caused INTERIOR damage to my property. 

Not to mention chewed off outside dryer vents & the exterior Hi Efficiency PVC externals.

Interior and exterior photos. 3.