I installed my own on our previous Honda CRV and had no problem. The procedure for the Fit is probably similar. There is a lot of plastic to remove to get down to the bumper area. The Roadmaster base plate brackets fit perfectly with no need for any alterations.
We are now towing a 2008 Fit and had the base plates installed due to time constraints. One thing you should know about the Fit is that it is
very low to the ground. We have drug the front end several times and have worn off some of the plastic buttons that attach the bottom skid plate to the lower bumper area. Other than that towing the Fit has been great.
Good luck!