"We will do it gently"
Indeed, "it" begs for an infix. We have no clue here what's it's about. In that case it's best to use the singular infix from the N-group: Tutaifanya taratibu.
Should there be some kind of object infix her? If so what? If not why not?
There is need for an object infix because of "it". Since there is no context as to what object "it" is referring to, you can pick any that makes sense. I picked "-ki-" object infix to make the sentence "Tutakifanya taratibu"