You file a Petition for Decree of Divorce with your jurisdiction’s district court.
No. Residency is established at the time of filing.
Not always. Some courts are willing to (and, in fact, some Kansas Courts automatically) bifurcate the issues, so that the divorce can be entered prior to resolving the other issues.
At any time, as long as at least one of the parties has resided in Kansas for at least 60 days prior to filing for divorce.
Although you can represent yourself in a divorce case, it is advisable to hire an attorney to represent your interests in a divorce. It is very risky for most in the case of a contested divorce due to lack of knowledge on court procedure and evidence.