Do your byelaws under the Societies Registration Act provide for the dissolution of the Association? If so, follow that procedure. If i not, there will be procedure to amend the byelaws of the Association.
You call a meeting of the General Body and pass the following resolutions
1. To dissolve the existing Society. The requirement will be same as that for amendment of the byelaws.
2. To form yourselves into an Association and register under the Karnataka Act. Form a provisional managing committee for the purpose. Draw up the byelaws of the new Association. The Association under the Karnataka Act will have certain requirements.You may have to purchase the necessary forms, draft byelaws etc. You will have to inquire at the respective Karnataka Government Office. Or you may get them from the internet. You will have draft the specifc byelaws for your Association. Call a general meeting and pass the necessary resolutions. Alternatively right now you can do all the home work and pass the resolutions at the first meeting itself.
3. Your present association byelaws will be saying what to do with the assets of the association in the event of its dissolution. Subject to that, you pass a resolution to tranfer the assets and liabilities from the old association to the new association. Generally if an association has creditors, their concurrence will be required for the transfer of liabilities. Creditors are those from whom the old association may have taken loans, contractors or suppliers of goods for whom payments are due etc.
After the formation and registration of the new association you approach your bank open new account in the name of the new assocition. Transfer all the funds from the account of the old association to that of the new association. Close the account of the old association. It will be convenient if the last managing committee of the old association and the first managing committee of the new association are the same.
After the closing of the account, submit all documents for the dissolution of the old association at the Societies registration office. There may be other formalities for the dissolution, which you can know from the registrar's office. I think Charity Commissioner is the registrar for this purpose.
There may be variations in the above procedure depending on the laws of Karnataka. You will come to know of them as and when you proceed. Good Luck.