I have 2 Magento websites (Web A and Web B with different Magento installations) but I need a single Magento installation with 2 websites how to merge 2 different websites to a single installation with multi-website.

Present structure

Web A -> database A

products= 125

customers = 2000

orders = 4677

Web B -> Database B

products = 543

customers= 24590

orders = 67090

now I need

Web A, Web B -> database

two Databases into single database same links like customers order and products all data

how to merge this data is there any efficient way