16 September 2013
You need to form a pvt ltd company and take over the assets and liabilities of the Prop Firm as going concern basis. Shares will be issued in lieu of purchase consideration.
18 September 2013
I think you are asking about conversion of Proprietorship Firm into Pvt Ltd company.
Conversion is not possible since an Individual can not merge with a company. So a pvt ltd company is required to be formed in its usual process. Them under an agreement the business will be taken over by the Company from firm and the Company will run the business in its own name. Proprietorship Business firm will then cease to exist.