There is no special provision to transfer proprietorship. He can execute a gift deed in your favour for all the fixed assets of the proprietorship (e.g. shop, etc.). He can also execute a transfer deed transfering the proprietorship name to you. However, he cannot transfer the bank account or the liabilities of the firm. You will need to open another bank account in the name of the proprietorship with you as the proprietor. He shall remain liable to pay all the creditors of the firm, till you pay them off.