I quoted an investor for rodent removal and repairs for a rental house and it was around $5400. Needless to say, they didn't want to pay it because it sounds like it can be done cheaper but this is the only way I could say the problem is eliminated. The attic has squirrels and large raccoons living in the attic space. The cost broken down was the following work.
Tree cut down and limbs cut back from over house and haul off
Several tall shrubbery removed from against house and haul off
Broken gutters removed and new gutters installed for front of the house
Cornice package repair and paint several locations
Decking repair and new shingles in section
Rodent removal and feces removal
New insulation and removal of feces-embedded insulation
HVAC drain pain drain pipe modification
Note: I'm not sure what a handyman could do other than this to remediate the infestation but this is what I would have to do to stand by the work.