Technically yes another mobile and apu chip would be able to do it say and a10 or a8. Would I recommend it? Never because of the difficulty in doing it right and the laptop isn't worth spending that much money upgrading it
The best I know which is free is WPS office which has both android and apple apps. It is fully compatable with the full Microsoft office suite and saves in same format. I have uses the app for years and brilliant
Replacing parts is very hard in a laptop so your best bet is a refurbished laptop from PC world or somewhere like that which means you can get a good laptop for two thirds the price of new