A partnership can be dissolved on the happening of certain contingencies, subject to contract between the partners a firm is dissolved.
a) if constituted for a fixed term, by expiry of that term;
b) if constituted to carry out one or more adventures or undertakings, by the completion thereof;
c)by the death of a partner;
d) by the adjudication of a partner as an insolvent.
You need to make a dissolution deed by all the partners and get it registered. Apart from it you need to surrender your firm's PAN with A.O alongwith a copy of dissolution deed.
The division of properties and assets between partners in the event of dissolution of the partnership firm may be in the ratio mentioned by you . Till division takes place, no partner has any specific right to any specific property of the firm.